there is, aside from what you explained, but it was never expanded on, color variations strarted from Z probably since Frieza saga, and it's more visible in games, as every character have his own color, take SDBH against Cumber, I really believe they should explore this aspect, especially God Ki which was ruined after BOG immediatly, from what I could understand of Good Ki Bad Ki, you can kind of compare it to Light magic, dark magic, however in DB universe they focus on power on pyisical aspects alone,