My rankin dragon gets leapord type sports all over he's underbelly when he is in he's viv but as soon as I get him out they disappear and he's happy but the viv is right tempretures and he has got tiles and reptile carpet as the substrate so I don't no what to do
The dark spots are likely related to him darkening his skin to absorb more light/heat. It's a basking reaction. It's normal and nothing to worry about. If he's alert and active and he's eating well he's probably in good shape.
They are on the under side of hes belly but only appear when in the viv but he is active out of the viv and eats worms but does not like much vegtables
Yeah that's normal. Especially when they're little. How old is he? It's also common for younger dragons to want bugs instead of salads because they need the protein to support large growth spurts.
If he's 2 then he will be fully grown. I'd keep offering salads and add as much variety as you can until you come across some items he likes. Squash cut into worm shapes and chopped green beans are popular with my guys. Collard greens and turnip greens are also a good staple to offer. The salads should be about 80% of his diet but if he isn't used to it, it may take some time for him to adjust to a proper diet.
Rankin's are neat little critters. I have 4, it was 5 but I gave a male away. Do you have a picture of yours? I would love to see it.
This picture is kind of old...but this is one of mine.