What should you do if your dog vomits something other than 'yellow stuff' 'foamy stuff' or food?

Dogs vomit for a lot of reasons. If the vomit appears normal, ie it is yellow, yellow and foamy, white and foamy, mostly water, or food, then it is probably okay so long as he doesn't keep doing it more than occasionally. However, if he vomits something dark, something that looks like coffee grounds, worms, blood, or something else you cannot identify, then he needs urgent veterinary care.