4D space-filling will give you the answers, and vice versa.

Hint 2

You only need three out of four coloured coordinates to find your destination in this unusual space, and one to write.

Hint 3

Use the (R,Y,G,B) coordinates to find your starting points in the 3D grid of truncated octahedrons, then write your puzzle answers along the axis whose coordinate was kept at zero. Then look at your projected letter map from the viewpoints provided.