If I stain or dye shingles I always color the shingles first, but painting shingles first is either tedious from painting them one-at-a-time and laying them out to dry, or intensely frantic from batch painting and then keeping them from sticking to each other by rubbing and stirring the whole time as they dry with the risk of having them all turn into a big messy clump if I can't keep up (I have done this, it's really a two person job and they have to be 'do-or-die' relentlessly committed for the first 10 - 20 minutes... very high impact!).
A much more reasonable alternative is to shingle the house with un-painted shingles, then mix regular interior semi-gloss latex paint (the same stuff recommended for the dollhouse) 50/50 with water, tip the house on its back, and paint the front roof with a foam brush. Keep the brush lean so the paint wash doesn't flood the shingles and so there's as little water-impact on the shingles as possible (water curls shingles and less water curls them less).
Tipping the house back to do the Front Roof is what allows the brush to be lean. If the house is upright, getting the wash up against the bottom of the next-higher-course requires flooding the shingles to puddle the wash up under the next-higher-course's ends, and shingles do what they are designed to do: they shed the puddle and drip it all over the place and leave un-painted places and get paint on every place you wished it didn't!!! (get the idea? It's a mess).
But when the house is tipped back you don't have to puddle the paint at all and everything is much more civilized. Tip the house on the side to do a Gable or Side Roof and to the front to do the Back. You still have to be careful, but painting an upright house is nearly impossible and painting a house tipped this-way-and-that is possible (tip the house just enough to get the Porch Roof flat).
Paint-wash colors the shingles but leaves the wood look.
This technique is not easier than pre-staining, but it is what I do when I need a paint-color on the shingles, or if I need to change the color of a shingled roof using stain.
