[Xmonad] border colours

I note that normalBorderColor is a grey, and focusedBorderColor is red. I don't find these particularly distinguishable. Likely that's because I'm in the 10% or so of men who have red-green colour blindness (I believe it's normally the red receptor that's missing). Not a big deal, since this is easily changed. But maybe there's some alternative that would be acceptable to almost everyone? I find focusedBorderColor = "#ff00ff" to be nicely visible. Maybe it's too obvious?