The Rage/Red Lanterns are worse than the Sinestro Corps (Yellow/Fear); the Star Sapphires/Violet Lanterns believe that with enough love any criminal can be rehabilitated (they may be foolish but they're hot); and the Blue Lanterns can take Hope and charge the Green Lanterns with more energy as they try to establish Universal peace.
The Red Lantern Corps T-shirts hit the market and are pretty cool: bright red with a simple logo very similar to most the GL shirts you see. Sinestro Corps shirts are a mustard gold which aren't too bad considering they could have been sunshine yellow. The Star Sapphires just came out and I expected the shirts to be pink like the costumes in the comics. Don't argue with me - they are hot pink not violet! So because they are called Violet Lanterns, the Tees are actually deep purple and don't at all resemble their comic book counterparts. The Blue ones coming out in April are called "indigo" but are really bright blue - however in the comics, they are colored as bright blue.
I took the sleeves from my Umbrella Academy shirt and repurposed them to VL Tee. Then I marked up where I wanted to cut so that I could create a design that felt like a comic book costume. I was going for the John Stewart "pointed" look but alas, I feel I fell short and created something more like "cheerleader."
What started out solid purple, now looks like this:
