CMYK, spot colors, etc.

Here is my problem: I have a collection of colors that I would like to use in a series of photographs, and I would like to constrain my image to use only those colors or combinations thereof. It will be limited color palette, but that is fine, and I would like my most saturated colors to match the sample colors. I don’t have good painting skills nor do I have a drawing tablet to make doing such things easier, otherwise I would simply paint the colors on my subjects. I don’t have the funding or talent to actually put together a scene that will have those colors naturally in it.

I know that photos printed on commercial press are printed with a combination of cyan, magenta, yellow, and black ink.  I’ve created many CMYK separations from my photos and am fairly comfortable with the process. The printer sends me an ICC profile that I use in proofing and converting my images, and I often edit in CMYK in order to get the most out of the color I have available.

OK, but what if I want to print using an arbitrary combination of inks? Not the standard CMYK inks, but something different? How is this done? In Photoshop, I’ve looked at the Custom CMYK feature, but I’m not too certain on how to proceed with that, if indeed that is the best course of action. Spot colors seem promising, but the instructions on how to use them seem unclear.

Does anyone have any suggestions?  Thanks!

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