I have been using these lights for three years, two over my 65g and one over my frag tank.
These lights are very powerful, at 8”,can push 750-800 par under the fixture.
I would follow the manufactures recommendations at the beginning, and move upwards slowly to
@lapin suggestion of 70% blue, 10 (maybe 20%) white.
Definitely move upwards from 8” to 12” or “14 so the colors defuse well.
After two years, I have got mine up to 100% blue and 20% white and they have been that intensity for a year now.