I have quite a few seed ideas for Leaf / Looseleaf Lettuce:
If you are looking for a green variety, then check out the following:
Black Seeded Simpson – this variety is known for tolerating the summer heat.
Ezrilla
If you want a spark of color in your lettuce, then check out these varieties:
Brentwood Leaf – this one has burgundy leaves.
New Red Fire – this variety has green leaves tipped with red.
Red Sails – this one was an All America selections winner!
Prizehead – lime green leaves with purple/bronze tips.
Some varieties come in green and red: