If you are wanting to add just a bit of colour there is a process called "dry brushing". Put a bit of paint on a wide brush, then take most of the paint off by brushing on a paper towel, when you think there is no more paint on the brush, take the brush to your wood and lightly brush over the area you want colour on. I hope this makes sense. Another way to look at it is like a lady applying blush makeup to her cheeks - just a very light hand!!