You tint Awlgrip with Awlgrip - darker blue with a bit of white equals a lighter blue. More complex colors are a lot tougher, but still can be done. Use an eye dropper to add the two (hopefully only two) colors and write down how many drops of each. You have to judge when you have it right from dry, not wet paint. Mix it up when you are ready to use it, adding the catalyst at that time.
I touch up Awlgrip all the time, using an Iwaki air brush, which lets you put on the paint with great precision over a small prepped area. Somewhere on this forum I described in detail the technique, but I can't find it now. The basic idea is to wet sand the area with 600 grit, then dust on to glisten the top coats. Primer coats are required if over steel or aluminum. Don't use masking tape, but wet sand with 1000 to 2000 grit to remove the overspray and use the wet sanding to match the fade of the surrounding paint, since the Awlgrip unsanded will be much more glossy.
Because your paint is colored, you should know that you will never get it to match well enough that you won't be able to see it, but if you're careful you should get it close enough to be happy with the job.
Hope that helps.
p.s. Delfin was painted in 2002 and people stopping by will frequently comment that she must have been newly painted. No credit to me, but if maintained properly, Awlgrip will last a very long time.
"Dad always thought laughter was the best medicine, which I guess is why several of us died of tuberculosis." - Jack Handy