Gamboge

Permanent synthetic, tint.

This pigment works (somewhat) on a three color palette,
making a dark that leans toward the Green side but it makes excellent Oranges and Reds.

The mass-tone color is a light yellow oxide hue.

It's under-tone is not a bright yellow and it's top-tone has very little of the dual-tone qualities, The color just stands out too much in a painting to use it as a primary color. At best it's a specialty color.