Tinted lacquer
At my local Paint Mart, I bought 2 oz. containers of the primary colors plus black and brown by "Rudd". These I mix with Deft, and usually just "wing it"
regarding the amount of dye/lacquer ratios. Building coats and visualizing what 'many' more coats will look like, I add a little more red to the brown, or a little more black to the brown, yellow to the red etc.
The light that you use is critical to achieve the desired effect. Under flourescents the colors are dramatically different than under quartz halogen, and different still from outdoor ambient light.
The piece shown here is Myrtle. Four sessions of 3 coats each with sanding to 800 between sessions created a stunning effect to an otherwise plain-jane wood.