diff --git a/rtengine/improcfun.cc b/rtengine/improcfun.cc
index 42cbb6f20..052f13d08 100644
--- a/rtengine/improcfun.cc
+++ b/rtengine/improcfun.cc
@@ -7199,7 +7199,7 @@ SSEFUNCTION void ImProcFunctions::lab2rgb (const LabImage &src, Imagefloat &dst,
 */
 void ImProcFunctions::colorToningLabGrid(LabImage *lab)
 {
-    const float factor = ColorToningParams::LABGRID_CORR_MAX * 1.6f;
+    const float factor = ColorToningParams::LABGRID_CORR_MAX * 3.f;
     float a_scale = (params->colorToning.labgridAHigh - params->colorToning.labgridALow) / factor;
     float a_base = params->colorToning.labgridALow;
     float b_scale = (params->colorToning.labgridBHigh - params->colorToning.labgridBLow) / factor;
diff --git a/rtengine/procparams.cc b/rtengine/procparams.cc
index 336f32379..4b8ccf71a 100644
--- a/rtengine/procparams.cc
+++ b/rtengine/procparams.cc
@@ -618,6 +618,8 @@ bool LocalContrastParams::operator!=(const LocalContrastParams &other) const
 }
 
 
+const double ColorToningParams::LABGRID_CORR_MAX = 12000.f;
+
 ColorToningParams::ColorToningParams() :
     enabled(false),
     autosat(true),
diff --git a/rtengine/procparams.h b/rtengine/procparams.h
index 7aed263ea..7cc80b313 100644
--- a/rtengine/procparams.h
+++ b/rtengine/procparams.h
@@ -452,7 +452,7 @@ struct ColorToningParams {
     double labgridBLow;
     double labgridAHigh;
     double labgridBHigh;
-    static constexpr double LABGRID_CORR_MAX = 8000.f;
+    static const double LABGRID_CORR_MAX;
 
     ColorToningParams();
 
diff --git a/rtgui/colortoning.cc b/rtgui/colortoning.cc
index 38e0630d4..9a50c0730 100644
--- a/rtgui/colortoning.cc
+++ b/rtgui/colortoning.cc
@@ -119,19 +119,17 @@ public:
         const int cells = 8;
         float step = rtengine::ColorToningParams::LABGRID_CORR_MAX / float(cells/2);
         for (int j = 0; j < cells; j++) {
-            for(int i = 0; i < cells; i++) {
+            for (int i = 0; i < cells; i++) {
                 float R, G, B;
                 float x, y, z;
                 int ii = i - cells/2;
                 int jj = j - cells/2;
-                float a = step * (ii + 0.5) * 1.5;
-                float b = step * (jj + 0.5) * 1.5;
+                float a = step * (ii + 0.5);
+                float b = step * (jj + 0.5);
                 Color::Lab2XYZ(25000.f, a, b, x, y, z);
                 Color::xyz2srgb(x, y, z, R, G, B);
                 cr->set_source_rgb(R / 65535.f, G / 65535.f, B / 65535.f);
-                cr->rectangle(width * i / (float)cells, height * j / (float)cells,
-                                width / (float)cells - 1,
-                                height / (float)cells - 1);
+                cr->rectangle(width * i / float(cells), height * j / float(cells), width / float(cells) - 1, height / float(cells) - 1);
                 cr->fill();
             }
         }
diff --git a/rtgui/paramsedited.h b/rtgui/paramsedited.h
index c49b60eaa..6de5d52e4 100644
--- a/rtgui/paramsedited.h
+++ b/rtgui/paramsedited.h
@@ -174,7 +174,6 @@ public:
     bool labgridBLow;
     bool labgridAHigh;
     bool labgridBHigh;
-    bool labgridSaturation;
 };
 
 class SharpenEdgeParamsEdited