Choose a discreet glass for the " main " surface. For the windows you can choose intense bright colors or as in my illustrations here small pieces of dichroic glass ( dichroic coated colorless structural glass ).
Depending on the lighting and the viewing angle, the dichroic appears in a different color. Structured dichroic glass ( granite structure or ripple structure ) further enhances this effect - these dichroic glasses appear even more vivid.
Dichroic is a bit more expensive, but not prohibitively so and you only need small pieces...