Pepper, roasted or not. Fruits obviously. Veg (sweet potato is a good orange colour), cucumber.
I know exactly what you mean about the beigeness, all the things you kind of naturally offer are a bit dull/samey looking. But I don't know if that is me projecting my views or whether DS (8mo BLW) is really bothered.
I think as long as you keep a bit of variety then its ok. I don't really do 'pudding' either so give fruit in between/alongside beige stuff so kepe it more interesting.
Yep avocado - that's what I meant, not advocado ! Pickled beetroot is quite salty so I would go for fresh. You can bake it or boil it. Deliaonline has ideas on how to cook it. Also, how about asparagus spears ?