Just go for it, most of my work is coloured and or textured, the beauty is, you can normally take a fine cut or sand the bits you don't like and start again. Airbrush works well if you want to carefully blend colours, an artists mouth diffuser works well but not as accurate for fine blending, if you want to keep colours seperate and defined, then a burnt line made either with piece of Formica with the lathe spinning or pyrography machine if pattern is random.
Found birch ply a good base to start playing with colours and textures, and shows how good or bad colours are blending as the the ply is pale, when working on darker woods you are a bit more limited with what product/colours will show up. All trial and error tbh.
