They all seem to be tiger tooth. Its hard to see how solid the white is with the bright light coming from behind the shrimp, but the first pic looks to be decent solid white, although with the yellowish-red on the side of the heads, that may classified as a lower grade than S, but I'm not a super expert on them, so I'll reserve the final judgement for others.
tetra liquid test kits, i never use strips for anything. KH is the measure of carbonate hardness. Yeah i was a bit unsure of the grades because although they have the tiger tooth, the whites aren't as solid as they could be