We have a big application on the site and we have a few links which are, let\'s say blue color like the blue links on this site. Now I want to make some other links, but wit
See my comment on Ctford's reply.
I'd think the easy way to lighten a color would be to take each of the RGB components, add to 0xff and divide by 2. If that doesn't give the exact results you want, take 0xff minus the current value times some constant and then add back to the current value. For example if you want to shift 1/3 of the way toward white, take (0xff - current)/3+current.
You'd have to play with it to see what results you got. I would worry that with this simple a formula, a factor big enough to make dark colors fade nicely might make light colors turn completely white, while a factor small enough to make light colors only lighten a little might make dark colors not lighten enough.
Still, I think going by a fraction of the distance to white is more promising than a fixed number of steps.