I shall ignore that horrible attack on my precarious sanity.
For this one, I'd suggest doing a little testing on a hidden area. Try with marker pens or even better some acrylic dye which you can dilute.
Start LIGHT and expect to use several layers.
Most art supply stores carry them. Re-create a discoloured spot with some more of the same vds and test away. You want to find a colour that won't give you a darker spot though that would probably be an improvement.
I wouldn't want to heat setting a crayon on a microfibre, just a guess as I have not actually tried that and until you KNOW what fibre you're dealing with it would be risky.
But as Bill says if it can lose dye, it can probably be re-dyed.
Don't feel bad Jim. Take a look at these 2 chairs that Bill the cleaner um "cleaned". Actually they look better in white but the gold color is how the chairs used to look before......... well lets not go there.
This is also what can happen to your hair from drinking too much coffee or spending too much time out in the sun bike riding.