I thought it would be easy, but it doesn't seem to work as I expect. maybe my expectations are wrong...
I have a very simple image, 32-bit CMYK which is just black & white. I want to change all the black to Cyan. Should be easy, I just use rectangle mask to mark out the area I want then go to "Adjust->Replace Colors..." and it comes up with a dialog. So far so good.
I use the color picker to select black as the source I want to change, then I choose the color to change to, either with color picker or manually mixing it to pure Cyan. The colour does change, to something blue-ish or cyan-ish, but not what I specified. Same deal if I try with Magenta. It's close, but not quite.
If I just fill with Cyan, it does indeed come out the right color.
Is there any tutorial on how this is supposed to be used?
IBall said:The colour does change, to something blue-ish or cyan-ish, but not what I specified.
It sounds to me as if your colour management settings are having an unwanted effect here.
I'm testing it here with colour management off and I am getting pure cyan. But I'm using X4, which might not work completely the same as X5.
Hmmm... maybe my limited understanding of color management is wrong, but when I ask for Cyan (e.g. CMYK = 100,0,0,0), I should always get CMYK = 100,0,0,0 regardless of what profile is active or if I have colour management on or off. The difference is what it actually looks like, no?
When I switch between different profiles in the document, for example, picking Photoshop 5 Default CMYK, on my monitor, the white looks slightly blue-ish. However, the color picker still indicates the correct color. White is CMYK = 0,0,0,0 despite the blue-ish tint. The problem is using the Replace Color function, it doesn't do this. The actual color replaced isn't correct. If I specify CMYK = 100,0,0,0 as the replacement color I instead get something (for example) like CMYK=77,23,0,0
Even if it were color management stuff kicking in, should that happen when I do a normal flood fill? That behaves as I expect, when I ask for CMYK=100,0,0,0 I actually do get that color (regardless of what it appears like on my monitor).
I think X5 doesn't have CM off mode, the best I can find is the simulate CMYK off or emulate X4 mode and neither of these help.