The oil crayons from Filia, a Danish company, feature transparent, lightfast colors that blend exceptionally well. These hard, oil crayons can be used to create a watercolor paint effect by mixing them with a sponge and turpentine. Alternatively, you can use your fingertips to shade, mix, and spread the pigments on paper. Colors include black, dark brown, dark blue, pale green, red, vermilion, orange, yellow, white, blue violet, pale blue, dark green, red violet, ultramarine, pale brown, pale orange, pale yellow, and grey.