(Sorry if this is stupid question)

Pre 1.22 there was a clear message when crafting was unstable.

Now it does not use word that says it is unstable. Only that it is Rainbow or Red. (At least so far as I've seen in my few crafting attempts).

Can someone tell me what 'word' I need to look for to know it is unstable. Unsure if 'Rainbow' or 'Red' means its unstable (or just pretty ^.^;; )

Thank you.