Quartz, NSColor and color?

Question

iPhone

How can I convert colors from a layout in Photoshop to NSColor colors? No matter how much he fought, they constantly differ, as if brighter.
How I solved problems:
1. Made me look

[[NSColor colorWithCalibratedRed:R/255.0f green:G/255.0f blue:B/255.0f alpha:1.0] set];

2. Changed the color space to sRGB

NSColorSpace *sRGB = [NSColorSpace sRGBColorSpace];

Already better, but still brighter.
With this photoshop, the layout is in RGB / 8, and for the experiment it was also translated into sRGB, but nothing helped, the colors did not change.
I don’t know what to do anymore, I rummaged through the entire stack and Google.
Can someone advise some converters or some other tricky ways?

Answer 1

And if the alpha is reduced a bit?
[UIColor colorWithRed:0.0 green:1.0 blue:0.0 alpha:0.5]
On a black background of course.