Hide/Unhide Non-contiguous rows based on Data Validation Selection

Cell B6 has a data validation list with 4 options. Depending on the selection, certain rows should be hidden.

If b6="N/A", all rows should be visible.
If b6="RED", rows 9-12 should be hidden. Rows 7-8 visible.
If b6="GREEN", rows 7-8 and 11-12 should be hidden. Rows 9-10 visible.
If b6="BLUE", rows 7-10 should be hidden. Rows 11-12 visible.

I have been experimenting with combinations of the basic code below but can't get what I am trying to accomplish. I am thinking there must be a better way. Thank you.

[.Rows("9:12").Hidden = (.Range("B6") = "RED")]