Originally Posted by E Maguyon
I wouldnt really define it as "cmyk correct" as cmyk correcting is used to make accurate skin color editing as well as ridding of any incorrect color casts, which these pictures are far from.
The grungy textures are just a seperate layer on overlay or hardlight mode of an image of your fave texture (ie: paper, concrete, etc.) on top of the original layer, adjust opacity and mask to your liking.
Maybe one technique used here to gain that "hazy" vintage look is to do a curves adj layer, and mess with each RGB channel curve to your liking and exagerrate that "flat/hazy" contrast by making the curve line "more horizontal" and/or maybe doing opposite s-curves and also adjusting each channel to exaggerate certain colors, like the green casts in these pics. Hope that made sense.
The grungy texture you are talking about. Is most likely a bad magazin scan. Not A texture overlay layer.
Not sure what the treadstarter is looking for in the image. But play around with the Hue/sat. sel col and color balance to achive the look you want.