symmetricTintMap
Colormap going from color -> tinted white -> color
Discussion
This function is used by plotPoissonFlowOverContours
c : 1x3 RGB color in [0 1]
N : total number of levels (even recommended)
tintStrength : fraction of c mixed into white at the center
Example: c = [0.2 0.6 0.8]; colormap(symmetricTintMap(c,256,0.05)); colorbar