Summary

The default priority icons on new projects are not accessible for red-green colour blind users.

The icons used for priority are green, orange and red, with no shape to distinguish them for a colour blind user.
The "medium", "high" and "highest" icons look the same to me from a normal viewing distance, and I need to get close to the screen to tell them apart (I'm colour deficient, the 12% of all men type).

The "low" and "lowest" icons look the same colour, but they are at least pointing down.

On other types of projects, they have either a double arrow head, or a dotted "stem" so that the colour is not the only indication of priority.

Steps to reproduce

1. Create a Business ==> Project Management type project. (or a Software project)
2. Create a "Task" issue.
3. Notice the priority icon and the available options for it by clicking on the field in the view issue page.

Expected Results.

It's possible to distinguish all priority options without relying on their colour as an indication.

Actual Results

It's not possible to distinguish all priority options without relying on their colour as an indication.

Workaround

Configure a different set of icons for each new project affected by this bug.