Although paint is a great "OOOPS" cover up on asphalt shingles, and can look great when the paint matches the shingle color, it's not at all an acceptable fix for the long term.
A) shingles fade quicker than the paint
B) Shingles when wet change color, usually darker, the painted ones won't and will stick out like a sore thumb.
And if you want to know WHY I know, just come by my house and I'll show you. (ALWAYS test at home where you can view longevity and effects from weather)
Best fix is to replace the shingles, which isn't that bad a proposition if they have extras around. Although the new ones will not have faded, but they will.
Then patching my roof with roof cement, I collected some of the gravel from the gutters and embedded them into the cement. That looked pretty damn good.