How about CMYK? Since you're using hues and all. And then you could come up with a set of fitting (or completely unrelated) words that sounded cool like
Colors May Yield Knowledge
Chromatic Men, Young Killers
Custom Mecha YK
Crazy Mode Yellow Kicks
Cyan Magenta Yellow Key
I dunno.
As for mechanics, I feel like using hue for health would undermine the mechanic you proposed initially? Unless the nature of the game has now changed. I can't really think of another way to visualize health right now (aside from a conventional health bar), but I think attaching it to hue color would make the game much more...boring.
Unless...it introduces some sort of health vs. score management scenario in which you will purposefully take damage to increase your score, or rely on health powerups to reset your hue when new enemies arrive and vice versa. It seems like a much more difficult thing to plan for though since it will be contingent upon the enemy wave design (unless the level design isn't wave-based?), because if it's random then the best bet for the player to get a high score would be to have max health so as to survive longer regardless of combos.
squadron vs. individual is an interesting choice, but how will you be able to control them all if they have independent colors? As a player, in something score-based I hate the feeling of relying on chance for a bulk of my points.
having multiple ship types is a definite must

hahaha