Dark costume auras?

[BLVD]

It would be awesome to have the same bright/dark customization for auras that you get for powers. Currently, if you try to make an aura black or a dark shade of any color, it will just look transparent.

 

For example, my Fiery Aura tanker has dark purple & black effects on the shields. He also has the fiery fists & eyes aura in purple but it's a bright purple that looks... out of place. Sometimes the bright/dark combo looks awesome but other times it would be nice to have a dark aura. Would this require too much development?