The bases look great, now paint your troops ;-)
I told myself that I would not paint them because I stopped playing Warhammer 40k 15 years ago and just got back into Kill Team because it takes less time .... but the urge to paint is real ... The books also brought me back. Have you read the novels?
Same here, hadn't played for about 13 years, the paints and washes have got a lot better. No, don't feel the need to read the books, just paint the models and occasional game with colleagues at work.
The different greens help me and my enemy to easily distinguish guardsmen from scions even in my unpainted state and from far away.