[shinesw]

Ever since I started doing work in CMYK a lot of my filters have been disabled. I switched back to RBG and they still seem to be disabled. What gives?

[tq4F7YKs]

The only way you can use the greyed out filters in CMYK mode, is to use the filters on each color layer.
Go to channels and switch to Yellow first, then you can use the filter. Repeat this process for each of the colors and that will fix it.

NEVER and I mean NEVER change a photo from RGB to CMYK then back again. It will screw up you image and you still won't have access to the filter.

[Pharmadryg]

Shit. Thanks Tim.

[farmarrl]

The problem is... RGB works well with saturated color and you will lose that when you switch to CMYK. Then if you convert back, that lost saturation will translate poorly.
Switching between the two isn't as noticeable on photographs, but can be very on graphics.

[ClapekDodki]

I guess I should have known this before hand. Until I started doing paid work, I never really dealt with having to make images print ready.