Consider switching security coverage icon to something similar to D.O.

Taking a look at this at MidCamp 2023. I agree with the above that it should be green. I experimented with just changing the line color of the existing icon, but it looked way too similar to the "Compatible with your Drupal installation" icon, which is a white checkmark inside a green circle on the admin/modules/browse/ctools page (for example):

Changing it to the solid green shield like on drupal.org looks a lot better, and this would be my recommendation:

Note that drupal.org uses a black icon with a green filter over it: filter: opacity(0.5) drop-shadow(0 0 0 #7cbc48) brightness(2). We could do it that way, but I say just make the icon itself green (#7cbc48). The current icon is images/blue-security-shield-icon.svg so the file name will need to be changed along with the icon itself. This file name is also referenced in the code itself, so a find-and-replace will be needed. Finally, there also needs to be a white version of the icon to replace images/blue-security-shield-icon--dark-color-scheme.svg.

Those two greens don't look great together. I'm not sure if we should borrow the two greens from .messages instead, maybe? Though I get that we should be consistent across d.o and the Project Browser, so I am in favor of this change.