diff --git a/src/light/drivers/DriverBase.h b/src/light/drivers/DriverBase.h
index ed02ec10..c3b95ed1 100644
--- a/src/light/drivers/DriverBase.h
+++ b/src/light/drivers/DriverBase.h
@@ -150,6 +150,23 @@ class DriverBase : public MoonModule {
 protected:
     Layer* layer_ = nullptr;
 
+    /// One light of a wiring wider than RGB, for correctToRgb, sized off the hot path by sizeLightScratch.
+    ScratchBuffer<uint8_t> lightScratch_{*this};
+    /// Size lightScratch_ to the wiring, saying so in the status when memory runs out; true when an RGB wiring needs none or the light fits.
+    bool sizeLightScratch() {
+        if (correction_.outChannels <= 3 || lightScratch_.resize(correction_.outChannels)) return true;
+        setStatus("not enough memory for one light of this fixture", Severity::Error);
+        return false;
+    }
+
+    /// Correct one light for a wire that carries RGB alone, reading red, green and blue where the profile puts them, 0 for a role it lacks; `scratch` holds one light of the wiring.
+    void correctToRgb(const uint8_t* src, uint8_t srcCh, uint8_t* scratch, uint8_t* rgb) const MM_NONBLOCKING {
+        correction_.apply(src, scratch, srcCh);
+        rgb[0] = correction_.offRed != Correction::kAbsent ? scratch[correction_.offRed] : 0;
+        rgb[1] = correction_.offGreen != Correction::kAbsent ? scratch[correction_.offGreen] : 0;
+        rgb[2] = correction_.offBlue != Correction::kAbsent ? scratch[correction_.offBlue] : 0;
+    }
+
     /// The correction scratch; the size differs per driver, so the caller passes the byte count and the lifecycle lives here.
     uint8_t* wire_ = nullptr;
     size_t   wireCap_ = 0;   // bytes the allocation returned (0 when it failed)
diff --git a/src/light/drivers/HlsDriver.h b/src/light/drivers/HlsDriver.h
index b7a4854c..cbf7a099 100644
--- a/src/light/drivers/HlsDriver.h
+++ b/src/light/drivers/HlsDriver.h
@@ -50,8 +50,8 @@ class HlsDriver : public DriverBase {
     /// Where the encoder's segments are written, under the filesystem mount and served at /hls/, the same literal the file server uses.
     static constexpr const char* kSegmentDir = "/.hls";
 
-    /// Bind the two scratch buffers to this module, so their memory is accounted for.
-    HlsDriver() : rgb_(*this), corrScratch_(*this) {}
+    /// Bind the frame buffer to this module, so its memory is accounted for.
+    HlsDriver() : rgb_(*this) {}
 
     /// The catalog tags shown on this driver's card.
     const char* tags() const override { return kTags; }
@@ -119,7 +119,7 @@ class HlsDriver : public DriverBase {
             setStatus("out of memory for the video frame", Severity::Error);
             return;
         }
-        if (correction_.outChannels > 3) corrScratch_.resize(correction_.outChannels);
+        if (!sizeLightScratch()) return;   // its status names the shortage
 
         // Only where the encoder writes segments to disk rather than keeping them in RAM.
         if constexpr (platform::hasFsSegments) {
@@ -193,7 +193,7 @@ class HlsDriver : public DriverBase {
 
         // Packed with the output correction, so the stream shows what the wall shows.
         uint8_t* dst = &rgb_[0];
-        const bool wide = outCh > 3 && corrScratch_.count() >= outCh;
+        const bool wide = outCh > 3 && lightScratch_.count() >= outCh;
         const size_t rowBytes = static_cast<size_t>(width_) * 3;
         for (nrOfLightsType i = 0; i < n; i++) {
             const uint8_t* s = src + static_cast<size_t>(i) * srcCh;
@@ -201,9 +201,7 @@ class HlsDriver : public DriverBase {
             if (outCh == 3) {
                 correction_.apply(s, rgb, srcCh);
             } else if (wide) {
-                uint8_t* c = &corrScratch_[0];
-                correction_.apply(s, c, srcCh);
-                rgb[0] = c[0]; rgb[1] = c[1]; rgb[2] = c[2];
+                correctToRgb(s, srcCh, &lightScratch_[0], rgb);
             } else {
                 rgb[0] = s[0]; rgb[1] = s[1]; rgb[2] = s[2];
             }
@@ -397,7 +395,6 @@ class HlsDriver : public DriverBase {
     std::atomic<uint32_t> droppedFrames_{0};
     uint32_t       lastReportedDrops_ = 0; ///< tick1s-only
     ScratchBuffer<uint8_t> rgb_;          ///< tight RGB staging, sized in prepare()
-    ScratchBuffer<uint8_t> corrScratch_;  ///< one corrected light, when the wiring is wider than RGB
     char           urlBuf_[64]{};
     char           statusBuf_[64]{};
 };
diff --git a/src/light/drivers/NdiDriver.h b/src/light/drivers/NdiDriver.h
index 11ee3fe0..17106260 100644
--- a/src/light/drivers/NdiDriver.h
+++ b/src/light/drivers/NdiDriver.h
@@ -46,8 +46,8 @@ class NdiDriver : public DriverBase {
     /// The catalog tag this driver carries.
     static constexpr const char* kTags = "🖥️";
 
-    /// Bind the two scratch buffers to this module, so their registration puts their memory in the report.
-    NdiDriver() : rgb_(*this), corrScratch_(*this) {}
+    /// Bind the frame buffer to this module, so its registration puts its memory in the report.
+    NdiDriver() : rgb_(*this) {}
 
     /// The catalog tags shown on this driver's card.
     const char* tags() const override { return kTags; }
@@ -94,7 +94,10 @@ class NdiDriver : public DriverBase {
             setStatus("out of memory for the NDI frame", Severity::Error);
             return;
         }
-        if (correction_.outChannels > 3) corrScratch_.resize(correction_.outChannels);
+        if (!sizeLightScratch()) {   // its status names the shortage
+            release();
+            return;
+        }
 
         std::snprintf(statusBuf_, sizeof(statusBuf_), "sending %ux%u at %u fps",
                       static_cast<unsigned>(width_), static_cast<unsigned>(height_),
@@ -130,16 +133,14 @@ class NdiDriver : public DriverBase {
         if (srcCh < 3) return;   // a non-color buffer (DMX roles) has no frame to send
 
         // A wider wiring corrects into a one-light scratch, since the protocol carries RGB only.
-        const bool wide = outCh > 3 && corrScratch_.count() >= outCh;
+        const bool wide = outCh > 3 && lightScratch_.count() >= outCh;
         for (nrOfLightsType i = 0; i < n; i++) {
             const uint8_t* s = src + static_cast<size_t>(i) * srcCh;
             uint8_t* d = dst + static_cast<size_t>(i) * 3;
             if (outCh == 3) {
                 correction_.apply(s, d, srcCh);
             } else if (wide) {
-                uint8_t* c = &corrScratch_[0];
-                correction_.apply(s, c, srcCh);
-                d[0] = c[0]; d[1] = c[1]; d[2] = c[2];
+                correctToRgb(s, srcCh, &lightScratch_[0], d);
             } else {
                 d[0] = s[0]; d[1] = s[1]; d[2] = s[2];   // passthrough, same fallback as NetworkSend
             }
@@ -164,7 +165,6 @@ class NdiDriver : public DriverBase {
     bool           open_   = false;
     uint32_t       lastSendMs_ = 0;
     ScratchBuffer<uint8_t> rgb_;          ///< tight RGB staging, sized in prepare()
-    ScratchBuffer<uint8_t> corrScratch_;  ///< one corrected light, when the wiring is wider than RGB
     char           statusBuf_[64]{};
 };
 
diff --git a/src/light/drivers/RtspDriver.h b/src/light/drivers/RtspDriver.h
index 0c7ad5af..c95d089c 100644
--- a/src/light/drivers/RtspDriver.h
+++ b/src/light/drivers/RtspDriver.h
@@ -51,8 +51,8 @@ class RtspDriver : public DriverBase {
     /// The catalog tag this driver carries.
     static constexpr const char* kTags = "🖥️";
 
-    /// Bind the scratch buffers to this module, so their memory is accounted for.
-    RtspDriver() : rgb_(*this), corrScratch_(*this) {}
+    /// Bind the frame buffer to this module, so its memory is accounted for.
+    RtspDriver() : rgb_(*this) {}
 
     /// The catalog tags shown on this driver's card.
     const char* tags() const override { return kTags; }
@@ -102,7 +102,7 @@ class RtspDriver : public DriverBase {
             setStatus("out of memory for the video frame", Severity::Error);
             return;
         }
-        if (correction_.outChannels > 3) corrScratch_.resize(correction_.outChannels);
+        if (!sizeLightScratch()) return;   // its status names the shortage
 
         platform::EncoderConfig cfg{};
         cfg.width       = static_cast<uint16_t>(width_);
@@ -266,7 +266,7 @@ class RtspDriver : public DriverBase {
         if (srcCh < 3) return;   // a non-color buffer (DMX roles) has no frame to send
 
         uint8_t* dst = rgb_.data();
-        const bool wide = outCh > 3 && corrScratch_.count() >= outCh;
+        const bool wide = outCh > 3 && lightScratch_.count() >= outCh;
         const size_t rowBytes = static_cast<size_t>(width_) * 3;
         for (nrOfLightsType i = 0; i < n; i++) {
             const uint8_t* s = src + static_cast<size_t>(i) * srcCh;
@@ -274,9 +274,7 @@ class RtspDriver : public DriverBase {
             if (outCh == 3) {
                 correction_.apply(s, rgb, srcCh);
             } else if (wide) {
-                uint8_t* c = corrScratch_.data();
-                correction_.apply(s, c, srcCh);
-                rgb[0] = c[0]; rgb[1] = c[1]; rgb[2] = c[2];
+                correctToRgb(s, srcCh, &lightScratch_[0], rgb);
             } else {
                 rgb[0] = s[0]; rgb[1] = s[1]; rgb[2] = s[2];
             }
@@ -341,7 +339,6 @@ class RtspDriver : public DriverBase {
 private:
     Buffer*  sourceBuffer_ = nullptr;
     ScratchBuffer<uint8_t> rgb_;
-    ScratchBuffer<uint8_t> corrScratch_;
 
     platform::TcpServer     control_;
     platform::TcpConnection client_;
diff --git a/test/unit/core/unit_ModuleContract.cpp b/test/unit/core/unit_ModuleContract.cpp
index b6eebe92..26511701 100644
--- a/test/unit/core/unit_ModuleContract.cpp
+++ b/test/unit/core/unit_ModuleContract.cpp
@@ -33,7 +33,7 @@ const std::vector<Known> kKeepsMemory = {
     {"Effects", "its Layer keeps the pixel buffer while disabled"},
     {"Layer", "its pixel buffer_ is a plain Buffer that release() does not free"},
     {"Drivers", "outputBuffer_ is a plain Buffer that release() does not free"},
-    {"NdiDriver", "release() is overridden without chaining to the base, so the rgb_ and corrScratch_ scratch buffers stay, where the NDI library loads and the buffers exist", true},
+    {"NdiDriver", "release() is overridden without chaining to the base, so the rgb_ and lightScratch_ scratch buffers stay, where the NDI library loads and the buffers exist", true},
 };
 
 // Types whose enabled flag does not gate them, which the lifecycle then cannot switch off.
@@ -154,7 +154,7 @@ Row place(uint8_t index) {
         s.prepareTree();
         for (int i = 0; i < 3; i++) { mm::platform::setTestNowMs(now); s.tick(); now += 1100; }
         row.dynamicAfter = dynamicTotal(*m);
-        // A module added by document is measured from before its add, less its own objects. A standalone one stood in the tree before beforeAdd was taken, so its objects are already in that baseline and only what it holds beyond them counts; its setup-time allocations are in the baseline too and are not covered. A module standing in the tree before the add has no add to measure from.
+        // Measured from before the add: a module added by document less its own objects, a standalone one, already in that baseline with its setup allocations, by what it holds beyond them. Others have no add.
         if (byDocument || standalone)
             row.heldAfterDisable = static_cast<long>(mm::platform::allocatedBytes()) - static_cast<long>(beforeAdd) - (byDocument ? static_cast<long>(objectBytes(*m)) : 0L);
         // Removed the way the API's DELETE removes it, a top-level module leaving with its tree; a module the API refuses to remove (PreviewDriver) is out of this check.
diff --git a/test/unit/light/unit_NdiDriver.cpp b/test/unit/light/unit_NdiDriver.cpp
index 785a4626..25cbdaca 100644
--- a/test/unit/light/unit_NdiDriver.cpp
+++ b/test/unit/light/unit_NdiDriver.cpp
@@ -10,11 +10,12 @@
 #include "light/layers/Buffer.h"
 #include "light/layouts/Layouts.h"
 #include "light/layouts/GridLayout.h"
+#include <memory>
 #include <string>
 
 namespace {
 
-// The NDI seams and virtual time are process-global, so a REQUIRE that aborts mid-case would strand a forced mode (or a frozen clock) for whichever test runs next, the classic passes-alone / fails-in-sequence flake. A scope guard restores both however the case leaves.
+// The NDI seams and virtual time are process-global, so a REQUIRE that aborts mid-case would strand a forced mode or a frozen clock for the next test, the passes-alone, fails-in-sequence flake; a guard restores both.
 struct NdiSeamGuard {
     explicit NdiSeamGuard(mm::platform::NdiTestMode mode) {
         mm::platform::setTestNdiMode(mode);
@@ -128,6 +129,32 @@ TEST_CASE("NdiDriver applies the driver's own brightness correction") {
     CHECK(f[0] > 0);
 }
 
+// A wire that carries RGB alone takes a wider profile's color from where the profile puts it, not its first three channels.
+TEST_CASE("NdiDriver sends a white-first profile's colors, not its white") {
+    NdiSeamGuard seam{mm::platform::NdiTestMode::ForceAvailable};
+    // On the heap: a driver and a layer outgrow a test's stack frame.
+    auto source = std::make_unique<mm::Buffer>();
+    auto driver = std::make_unique<mm::NdiDriver>();
+    auto wall = std::make_unique<Wall>(2, 1);
+    setUp(*driver, *source, *wall, 2);
+    auto wrgb = std::make_unique<mm::Correction>();
+    wrgb->curve = mm::Correction::Curve::Linear;
+    const mm::ChannelRole roles[4] = {mm::ChannelRole::White, mm::ChannelRole::Red, mm::ChannelRole::Green, mm::ChannelRole::Blue};
+    wrgb->rebuild(255, roles, 4);
+    driver->correctionForTest() = *wrgb;
+    driver->prepare();
+
+    paint(*source, 0, 10, 20, 30);
+
+    mm::platform::setTestNowMs(1000);
+    driver->tick();
+
+    REQUIRE(mm::platform::ndiTestFrameCount() == 1);
+    const uint8_t* f = mm::platform::ndiTestFrameData(0);
+    REQUIRE(f != nullptr);
+    CHECK(f[0] == 10); CHECK(f[1] == 20); CHECK(f[2] == 30);
+}
+
 // fps is a CEILING: a second tick inside the interval must not produce a second frame, or a fast render loop would flood the receiver with frames it never asked for.
 TEST_CASE("NdiDriver holds its frame rate to the fps ceiling") {
     NdiSeamGuard seam{mm::platform::NdiTestMode::ForceAvailable};