You've saved me! I've been trying to work out how to colour on photoshop for months! I've got a older version of PS, so I'm having to adapt, but it's working so far! I've done all the lineart, and now onto the colouring stage!
...why? I've heard lots of people say that but lots of googling has not brought me closer to *why* they say it. I can achieve really quite good results shading using the burn tool by turning the exposure down to >10% and just layering slowly. If there is a better method, I'd like to know it.
The main issue is controlling it past the original brush stroke. The Burn tool (used normally) changes the actual pixels. This is generally not a good thing to do, since it means you can't easily go back and change something much later on. What you can do, however, is using a Smart Levels Adjustment layer, bringing down the color to a darker shade, and then using a mask to color it in (the darkness of your brush on your mask determines the opacity of the shading that goes through). At that point, though, it's easier to just shade on another layer with a proper brush and color.