why different colors

[Максим98A2]

Hello everyone, please tell me why here on the rectangles the layer shows different colors.

[Marianne-Deiters · Accepted solution]

because the two fill layers have different colors.

[davescm · Accepted solution]

Your two squares are not the same colour.

The yellow channel in the right hand square is at 100%. The yellow in the left 99% .

The maths for blending each channel in colour dodge is Background/(1-Foreground).  In the case of CMYK the layer values are inverted before the maths and the result inverted after.

It all works smoothly until the foreground layer is 0% which inverted is 1 and the background is 100% which inverted inverted is 0.  That results in maths which is 0/(1-1) = 0/0  which gives an error for which 0 is used and is then inverted to become 100%. i.e. the channel remains at 100%

Dave