The presentation of security levels 2 and 3 is very similar at present. This should be improved in a way which is easy to perceive at a glance.
Level 2 should get a different color, like yellow.
And a different icon would be good, too. I propose to only change the background of the check mark icon to yellow, too.
For VSD I somewhat agree since this is the difference between a VD Compliant signature. For the community edition though level 2 is usually enough and should also be indicated as trustworthy. So I am currently in two minds about this.
Yellow indicates a warning. In the old days we used yellow in too many cases and people barely got a green. This raised more user questioned than it was helpful. There is also a problem with accessibility if we overload colors too much.
I can imagine a double check mark for level 3 for a large icon or even in the text line (similar to what is used by Conversations et al.)