In photoshop, after mixing red（255 0 0） and white（255 255 255） with “hard mix”, the result is white, but in krita, the result is red
Hard Mix (Photoshop)
This is the hard mix blending mode as it is implemented in photoshop.
Left: Dots are mixed in with the normal blending mode, on the Right: Dots are mixed in with hardmix.
This add the two values, and then checks if the value is above the maximum. If so it will output the maximum, otherwise the minimum.
In krita, there is no further classification for the case of A+B=255(A is the base color, B is the mixed color)
The information I found in the book is:
if A≥128, C=255
if A＜128, C=0
Test: A: 128 0 0 and B: 127 0 0
A：127 0 0 and B：128 0 0