How can I manually set the colors of cell type in the obs component of an AnnData table?

[srivarra]

I have an AnnData object, and i'm able to view generate scatterplot of the cells in UMAP space with the default colors. How can I manually set the colors? Such as cancer cells being "red". I tried to use link_views with the c_types being [ct.OBS_COLOR_ENCODING], however that didn't end up working.
Thank you!