If I use /give @p stained_hardened_clay X and X is a number between 0 and 15, it gives the right clay. If X is a number 16 or higher, it cycles through the block types and gives you that block, but calls it "White Stained Clay". (So /give...16 yields white clay that's actually white clay, /give...17 yields orange clay, but it's called white clay, etc. However, blocks of the same color with different ID's won't stack, obviously.
Steps to reproduce: Type /give @p stained_hardened_clay followed by any positive integer 16 or greater.