If, after painting a piece, you decide you wish it felt "warmer" - you can always glaze over it after it dries. This is possible with acrylic and oil paintings, but a little tougher to do on watercolors (though not impossible, just use a light hand and make sure you don't go over thick, granulated areas of paint).
My example below uses acrylic paints, but you can also do the same thing with oils! On the left is the original painting, on the right is the same painting with a layer of cadmium yellow dark mixed with a generous amount of glazing medium.
Using Acrylic paint:
- Allow you finished painting to dry.
- Mix some paint with glazing medium (you can also use matte or gloss medium). Ratios can vary depending on how much you'd like to tint your piece. Start with about 1:8 paint to medium and then mess around with the ratios to achieve the proper effect.
- Apply the glaze with a towel or soft cloth to cover as thoroughly as possible.
- After the glaze has dried go back and brighten up the white highlights of your piece.
- The steps are the same - you must allow the painting to dry first!
- Instead of acrylic medium, you'll need to use an oil medium. Utrecht makes a nice Glazing Medium, but you can also use Galkyd mixed with a tiny bit of stand oil to create a nice glazing medium.