For me it's less pictures and more abstract things. I can picture my mom's face right now, but it's about things like the quality of her gaze, tilt of her head and not an exact shape or image. When I imagine a beach I remember vividly the salt air, the warm sand, the waves rumble, the horizon all around, but it's not any kind of photorealistic picture. A sufer is a vague shape, maybe a human outline, plus movement vectors for the surfer and the waves.

I also have dreams that include complete source code to programs that I can edit in my dreams (and often works if I type it in, unless the programming language was also dreamed up). And I can visualize entire routes on well known roads and trails (hours and hours of them), but it's all about the turns, the rises and falls, the outlines of the view at any point along the way, the feeling of a place, but never any images.

Never any colors, come to think of it. Triangle? Sure, and I can rotate tetris peices in my head and slot them into place. But red triangle? No, it's just 3 angles with lines.