[docs] Update code snippet in docs for custom color palette (#32946)
[docs] Update code snippet in docs for custom color palette (#32946)

* test(Chip): add test case for custom color in theme palette

* fix(Chip): calculate contrastColor if custom color is provided in theme palette to avoid crash in alpha function

* revert changes

* update code snippet

* update docs

* improve indentation
mui-org/material-ui,mui-org/material-ui,mui-org/material-ui