By ©Jimi Wikman
A simple icon set for Priorities I use in my own Jira instance.
It uses colors to indicate priority / Severity ranging from full red in the blocker and then scale down in the color range down to purple for the lowest.
The symbols are simplified as well to make them as visible as possible.
Blocker - Full red with a blocked icon as the indicator. Highest - 7 sided background in deep red with a white exclamation mark. High - Orange triangle pointing upwards. Medium - Green circle Low - Blue triangle pointing downwards. Lowest - Three purple dashes.