Currently we are only able to modify, as called in game the “Base Color”, that is actually the Primary Color of the "Two-Tone" material, and the “Highlight” that is the secondary color. The true Base Tone for the “Two-Tone” material is always black and for the “Metal Flake” material is always white, I’ve made two examples with the brightest factory colors I’ve found, to prove that the “Two-Tone” base color is so dark that it’s unable to replicate bright two-tone colors.
Factory
Base Tone: Blue-ish green
Primary Color: Pale lime green
Highlight: Dark Green
Two-Tone color
Base Tone: Black
Primary Color: Pale lime green
Highlight: Dark Green
Another example:
Factory
Two-tone color
This one’s similar but still different. Although may not want to replicate factory colors that much, this will an awesome, and necessary tool for creatives to execute ideas with precision.