@Stern AlgorithmIn an oppressive world where even the very lights are designed to be bleak and cause a draining effect on the populace, the Strike Force teams costumes will be brightly colored with accents of neon to inspire the people. Additionally, the weapons of the Rangers will be made of hard light constructs (think Green Lantern style). Light plays a huge and important role here. The costumes themselves will look very streamlined and space inspired due to how these particular ranger powers were made. The mentor figure is going to be a middle manager for Galatec secretly working against them. Galatec is large enough that they've encountered other ranger teams on other worlds before, and they have won, thus confiscating their tech. So the mentor cobbled together what he (or she!) can from the remnants of past alien rangers.
OK, so light will be the unifying theme, but what about the diversifying theme? What will set our rangers apart from each other, theme-wise? For example, The original Might Morphin's theme was dinosaurs, so each ranger had a different dinosaur. Will we have unique 'elemental' powers? I'm hoping we all have different weapons, melee and ranged. For example, MMPR had different melee weapons (sword, bow ,axe, etc.), but everyone had the same blaster. If our ranged weapons were different, that would be cool, for example, dual pistol, assault rifle, sniper rifle, shotgun, etc. Of course they'd be the future space-y versions of said weapons. We will have zords, I hope.