Rgb model asserts that all colors can be described from 3 components (Red, Green, Blue)

Each dimension can be moved from 0 to 255

In a project, combine the light from the two focus, which unfortunately are not pure colored (neither R, G or B) but with the following schemes:
focus1 = [18,32,64]
focus2 = [128,16,32]
For each focus have a dimmer switch that goes from 0-1
a) Can you get the color [144,34,68]? Yes
b) Can you get the color [64,24,48]? No
c) Can you get the color [16,128,32]?No
d) Imagine other two focus with which one can generate the same colors that focus1 and focus2

Question

Rgb model asserts that all colors can be described from 3 components (Red, Green, Blue)

Each dimension can be moved from 0 to 255

In a project, combine the light from the two focus, which unfortunately are not pure colored (neither R, G or B) but with the following schemes:
focus1 = [18,32,64]
focus2 = [128,16,32]
For each focus have a dimmer switch that goes from 0-1
a) Can you get the color [144,34,68]? Yes
b) Can you get the color [64,24,48]? No
c) Can you get the color [16,128,32]?No
d) Imagine other two focus with which one can generate the same colors that focus1 and focus2