I think the tip and hint admonitions are OK as green, but I think blue would be a better color. The color green has an international context of "go", whereas blue has a context of "information".

Additionally I think important should be yellow, not green, as it is similar in purpose and context to caution.

See currrent examples:

https://pydata-sphinx-theme.readthedocs.io/en/stable/examples/kitchen-sink/admonitions.html

See also original discussion:

executablebooks/sphinx-book-theme#597 (comment)

I would be happy to submit a PR, upon consensus.