Q1: Can I make primary blue paint using red and yellow?
A1: No. Combining red and yellow creates orange. Under subtractive paint mixing, you cannot combine two secondary colors or warm spectrums to yield a primary blue. You can, however, mix true optical blue by combining pure process cyan with quinacridone magenta.
Q2: Why does my blue and yellow paint make brown instead of bright green?
A2: Your blue paint likely contains a warm, red undertone, such as ultramarine blue, or your yellow leans warm toward red, like cadmium yellow deep. Red, yellow, and blue combined yield brown or neutral gray. Switch to a cool, green-leaning blue (phthalo blue) and a cool lemon yellow for crisp, clean greens.
Q3: How do I make navy blue paint without it looking washed out?
A3: Avoid relying on black paint to darken your blue. Mix ultramarine blue with burnt umber in roughly a 3:1 ratio. The warm orange undertone of the umber deepens the value of the blue without deadening its chromatic brilliance, resulting in a rich, museum-grade navy.
Q4: What is the difference between French ultramarine and regular ultramarine?
A4: Historically, natural ultramarine came from crushed lapis lazuli stone, while French ultramarine designated the synthetic pigment created in 1828. Today, almost all commercial tubes labeled ultramarine or French ultramarine are identical synthetic formulations (PB29), though some brands label warmer, slightly redder batches as French ultramarine.
