Bug: Avatars with transparency aren't always transparent

[ginatrapani]

Transparent PNGs appear transparent in the colored-background activity stream, but not on the project page header, or project page activity stream:

https://makerba.se/p/o9825y/rebeccasgift

https://www.evernote.com/l/AAERAt0JgnNBnJbWkbb_b7mNkslz-JuKKXc

@anildash is there a CSS fix for respecting transparency?

[anildash]

Yeah, it was overridden as a deliberate design choice because a lot of transparent images look weird on our many vibrant colors. Easy to change that if you think we should?

[ginatrapani]

Treatment should be consistent. Right now the transparency looks great on the vibrant colors of the activity stream (at least the ones I've seen); why not support it on the gray page background as well?