This is an excellent site from the Green Barn Farm with genetic information and photos at different stages of a holland Lops life. I've found it very helpful with connecting genotypes with colors. Click Here.
From LaReau Lops & Cavies website, this is a long read but excellent information to beginner breeding ABC's. Click Here.
The Nature Trail Rabbitry has been an excellent teaching tool website with anything that you need to know about Holland Lops and Rabbit care. Click Here.