In various settings, I've simply reached for the big 'A' icon (e.g., in Microsoft Word) to then color-code background and/or foreground text to what makes sense to me. Mechanical, perhaps, to reach for that, though at the same time I know what those color codes meant to me.

(Alas, I lament that part of the GTD book where I believe it said color-coding wasn't such a big distinguishing factor for folders; my experience has been that color evokes certain emotions, very conducive to getting things done, like those from Chicago who proposed "Colour My World with hope of loving you.")