I have a very basic question about color use that someone will be able to answer easily. The background to the question is that (i) I am completely new to this scene of commercially[offset] print-ready material as distinct from what is required on screen (ii) I am using Mk IV (iii) I need spot colors set up for cmyk, and for now I need shades between black and white (e.g. light gray) for a simple design feature. My question is this: is the use of color keywords sufficient? Or in other words, have predefined color names like lighgray already been defined in, say cmyk terms behind the scenes, or must I instead \definecolor[lightgray][c=10,m=7,y=5,k=0], (or perhaps \definespotcolor with those dimensions, or do I need both)? Julian