I'm guessing everybody who wants to build a tuner has a (or at least access to a) colour deskjet printer.

So I wouldn't bother making hard copy manuals. The way I see it is it will only take a lot of your time and isn't really necessary anyway.
As you already pointed out it's probably also easier to read when it's printed in colour. So (I'm guessing here) most people will probaly print that .PDF anyway and use that instead if you decide to release it in addition to a hard copy manual. That's what I would do anyway.

So go on, take the easy route for a change. You know you want to!