Are those the Zoo Med Can O'Bloodworms? If so and they've been opened more than a week, you may want to discard them.
Whitish colored ones are usually dead or just bad. You could try dumping the whole can in a container of dechlorinated water and discard the 'bad' looking ones by pouring them out of the container and see how the normal ones look. I don't know if the sniff test works on these types of products.