The easiest way to get the colour you want for your model is to blend it yourself. Acrylic paints are the best to use for this. To coat your paper, paint it while it is still stuck to whatever flat surface you are using. If you want to paint paper not made by using spray adhesive or methyl cellulose, secure the paper to a flat surface using small pieces of masking tape. Use a gentle brush and layer the paint on very thinly several times, waiting several minutes between layers. When complete, remove the masking tape from the corners and paint these remaining spots. Making the paint thin allows it to flex without cracking when folded.
Keep in mind that since acrylic is water-based, it will bleed if you like to wet shape your models after folding. In this situation, you may need to reapply paint after shaping is completed.
