Top row:
Left:
Green dot = Renew is up

Middle:
White dot = PW:Shield is up, priority 2
Red dot = Weakened Soul, priority 1

Right:
Cyan dot = PW:Fortitude, priority 1
Blue dot = Shadow Protection, priority 2
Yellow dot = Fear Ward, priority 3
Whitish dot = Prayer of Mending, priority 1 (priority error?)

Bottom row:

Left:
Bluish triangle = Magic debuff

Middle:
Green triangle = Poisoned

Right:
Whitish triangle = Diseased, priority 2
Purple triangle = Cursed, priority 1

(Higher priority overwrites lower)

We are working on that, but want the graphical representation done just right. Don't hold your breath

Some of the colors were just plain wrong. I've tried to make them more intuitive.

PW:Fortitude now is cyan, like the center of the spell icon.

Weakened Soul is now red, more debuff-like

There was an error in the .toc of the 0.1 version of the priest set. That has been corrected and a new file has been uploaded.

I changed the .toc after testing the addon - and didn't retest before uploading