diff --git a/rtdata/languages/default b/rtdata/languages/default
index 80fb87cf4..628025e1b 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -2275,7 +2275,7 @@ TP_LOCALLAB_COFR;Color & Light - Small defects
 TP_LOCALLAB_COL_NAME;Name
 TP_LOCALLAB_COL_VIS;Status
 TP_LOCALLAB_COLORDE;Color preview selection ΔE and Intensity
-TP_LOCALLAB_COLORDE_TOOLTIP;Show preview selection ΔE in blue if negative and in green if positive.\nShow real modifications if positive, show enhanced modifications with blue and yellow if negative.\nThe intensity is function of the level.
+TP_LOCALLAB_COLORDE_TOOLTIP;Show preview selection ΔE in blue if negative and in green if positive.\nShow real modifications if positive, show enhanced modifications with blue and yellow if negative.\nThe intensity is function of the level.\nFor 'Denoise' the appearance is different.
 TP_LOCALLAB_COMPFRA;Levels Dynamic Laplacian Range Compression ƒ
 TP_LOCALLAB_COMPREFRA;Levels Dynamic Wavelet Range (un)Compression
 TP_LOCALLAB_COMPRESS_TOOLTIP;Use if necessary the module 'Clarity & Sharp mask and Blend & Soft Images' by adjusting 'Soft radius' to reduce artifacts.
diff --git a/rtengine/improcfun.h b/rtengine/improcfun.h
index af9b1e6e8..be5566483 100644
--- a/rtengine/improcfun.h
+++ b/rtengine/improcfun.h
@@ -344,8 +344,8 @@ public:
     void exlabLocal(local_params& lp, int bfh, int bfw, LabImage* bufexporig, LabImage* lab,  LUTf & hltonecurve, LUTf & shtonecurve, LUTf & tonecurve, float mean);
     void Exclude_Local(float **deltaso, float hueref, float chromaref, float lumaref, float sobelref, float meansobel, const struct local_params & lp, const LabImage * original, LabImage * transformed, const LabImage * rsv, const LabImage * reserv, int cx, int cy, int sk);
 
-    void DeNoise_Local(int call, const struct local_params& lp, LabImage * originalmask, int levred, float hueref, float lumaref, float chromaref, LabImage* original, LabImage* transformed, LabImage &tmp1, int cx, int cy, int sk);
-    void DeNoise(int call, int del,  float * slidL, float * slida, float * slidb, int aut, bool noiscfactiv, const struct local_params& lp, LabImage* originalmaskbl, int levred, float huerefblur, float lumarefblur, float chromarefblur, LabImage* original, LabImage* transformed, int cx, int cy, int sk);
+    void DeNoise_Local(int call, struct local_params& lp, LabImage * originalmask, int levred, float hueref, float lumaref, float chromaref, LabImage* original, LabImage* transformed, LabImage &tmp1, int cx, int cy, int sk);
+    void DeNoise(int call, int del,  float * slidL, float * slida, float * slidb, int aut, bool noiscfactiv, struct local_params& lp, LabImage* originalmaskbl, int levred, float huerefblur, float lumarefblur, float chromarefblur, LabImage* original, LabImage* transformed, int cx, int cy, int sk);
 
 
     void fftw_denoise(int GW, int GH, int max_numblox_W, int min_numblox_W, float **tmp1, array2D<float> *Lin,  int numThreads, const struct local_params & lp, int chrom);
diff --git a/rtengine/iplocallab.cc b/rtengine/iplocallab.cc
index 944cb42ec..d5557efc9 100644
--- a/rtengine/iplocallab.cc
+++ b/rtengine/iplocallab.cc
@@ -2511,7 +2511,7 @@ static void calcreducdE(float dE, float maxdE, float mindE, float maxdElim,  flo
         }
     }
 }
-void ImProcFunctions::DeNoise_Local(int call,  const struct local_params& lp, LabImage*originalmask, int levred, float hueref, float lumaref, float chromaref,  LabImage* original, LabImage* transformed, LabImage &tmp1, int cx, int cy, int sk)
+void ImProcFunctions::DeNoise_Local(int call,  struct local_params& lp, LabImage*originalmask, int levred, float hueref, float lumaref, float chromaref,  LabImage* original, LabImage* transformed, LabImage &tmp1, int cx, int cy, int sk)
 {
     //warning, but I hope used it next
     // local denoise and impulse
@@ -2526,6 +2526,10 @@ void ImProcFunctions::DeNoise_Local(int call,  const struct local_params& lp, La
     const int GW = transformed->W;
     const int GH = transformed->H;
 
+    if (lp.colorde == 0) {
+        lp.colorde = -1;//to avoid black
+    }
+
     float darklim = 5000.f;
     float aadark = -1.f;
     float bbdark = darklim;
@@ -2644,11 +2648,12 @@ void ImProcFunctions::DeNoise_Local(int call,  const struct local_params& lp, La
                     transformed->L[y][x] = CLIP(original->L[y][x] + difL);
                     transformed->a[y][x] = CLIPC((original->a[y][x] + difa) * factnoise);
                     transformed->b[y][x] = CLIPC((original->b[y][x] + difb) * factnoise) ;
+                    float amplabL = 2.f * lp.colorde;
 
                     if (blshow) {
-                        transformed->L[y][x] = CLIP(12000.f + 10.f * difL);// * 10.f empirical to can visualize modifications
-                        transformed->a[y][x] = CLIPC(10.f * difa);// * 10.f empirical to can visualize modifications
-                        transformed->b[y][x] = CLIPC(10.f * difb);// * 10.f empirical to can visualize modifications
+                        transformed->L[y][x] = CLIP(12000.f + amplabL * difL);// * 10.f empirical to can visualize modifications
+                        transformed->a[y][x] = CLIPC(amplabL * difa);// * 10.f empirical to can visualize modifications
+                        transformed->b[y][x] = CLIPC(amplabL * difb);// * 10.f empirical to can visualize modifications
                     } else if (previewbl) {
                         float difbdisp = (reducdEL +  reducdEa + reducdEb) * 10000.f * lp.colorde;
 
@@ -6200,6 +6205,17 @@ void ImProcFunctions::BlurNoise_Local(LabImage *tmp1, LabImage * originalmask, f
     kab /= SQR(327.68f);
     kL /= SQR(327.68f);
 
+    if (lp.colorde == 0) {
+        lp.colorde = -1;//to avoid black
+    }
+
+    float ampli = 1.f + fabs(lp.colorde);
+    ampli = 2.f + 0.5f * (ampli - 2.f);
+
+    float darklim = 5000.f;
+    float aadark = -1.f;
+    float bbdark = darklim;
+
     const bool usemaskbl = (lp.showmaskblmet == 2 || lp.enablMask || lp.showmaskblmet == 4);
     const bool usemaskall = (usemaskbl);
     const float radius = 3.f / sk;
@@ -6277,7 +6293,7 @@ void ImProcFunctions::BlurNoise_Local(LabImage *tmp1, LabImage * originalmask, f
                 const float chra = tmp1->a[y - ystart][x - xstart];
                 const float chrb = tmp1->b[y - ystart][x - xstart];
 
-                const float difL = (tmp1->L[y - ystart][x - xstart] - original->L[y][x]) * localFactor * reducdE;
+                float difL = (tmp1->L[y - ystart][x - xstart] - original->L[y][x]) * localFactor * reducdE;
                 transformed->L[y][x] = CLIP(original->L[y][x] + difL);
                 flia = flib = ((100.f + realstrchdE) / 100.f);
                 float difa = chra * flia - original->a[y][x];
@@ -6289,15 +6305,38 @@ void ImProcFunctions::BlurNoise_Local(LabImage *tmp1, LabImage * originalmask, f
                     transformed->a[y][x] = CLIPC(original->a[y][x] + difa);
                     transformed->b[y][x] = CLIPC(original->b[y][x] + difb);
                 }
+                    float maxdifab = max(fabs(difa), fabs(difb));
 
-                if (blshow) {
-                    transformed->L[y][x] = CLIP(12000.f + difL);
-                    transformed->a[y][x] = CLIPC(difa);
-                    transformed->b[y][x] = CLIPC(difb);
-                } else if (previewbl) {
-                    transformed->a[y][x] = 0.f;
-                    transformed->b[y][x] = (difb);
-                }
+                    if ((blshow) && lp.colorde < 0) { //show modifications whith use "b"
+                        //  (origshow && lp.colorde < 0) { //original Retinex
+                        transformed->a[y][x] = 0.f;
+                        transformed->b[y][x] = ampli * 8.f * difL * reducdE;
+                        transformed->L[y][x] = CLIP(12000.f + 0.5f * ampli * difL);
+
+                    } else if ((blshow) && lp.colorde > 0) {//show modifications whithout use "b"
+                        if (difL < 1000.f) {//if too low to be view use ab
+                            difL += 0.5f * maxdifab;
+                        }
+
+                        transformed->L[y][x] = CLIP(12000.f + 0.5f * ampli * difL);
+                        transformed->a[y][x] = CLIPC(ampli * difa);
+                        transformed->b[y][x] = CLIPC(ampli * difb);
+                    } else if (previewbl) {//show deltaE
+                        float difbdisp = reducdE * 10000.f * lp.colorde;
+
+                        if (transformed->L[y][x] < darklim) { //enhance dark luminance as user can see!
+                            float dark = transformed->L[y][x];
+                            transformed->L[y][x] = dark * aadark + bbdark;
+                        }
+
+                        if (lp.colorde <= 0) {
+                            transformed->a[y][x] = 0.f;
+                            transformed->b[y][x] = difbdisp;
+                        } else {
+                            transformed->a[y][x] = -difbdisp;
+                            transformed->b[y][x] = 0.f;
+                        }
+                    }
 
             }
         }
@@ -8671,7 +8710,7 @@ void ImProcFunctions::fftw_denoise(int GW, int GH, int max_numblox_W, int min_nu
 
 }
 
-void ImProcFunctions::DeNoise(int call, int del, float * slidL, float * slida, float * slidb, int aut,  bool noiscfactiv, const struct local_params & lp, LabImage * originalmaskbl, int levred, float huerefblur, float lumarefblur, float chromarefblur, LabImage * original, LabImage * transformed, int cx, int cy, int sk)
+void ImProcFunctions::DeNoise(int call, int del, float * slidL, float * slida, float * slidb, int aut,  bool noiscfactiv,  struct local_params & lp, LabImage * originalmaskbl, int levred, float huerefblur, float lumarefblur, float chromarefblur, LabImage * original, LabImage * transformed, int cx, int cy, int sk)
 {
 
 //local denoise