I have a black 70% opacity play button that sites on top of videos.
On light backgrounds it is very clear but obviously on darker backgrounds it nearly vanishes. I would like it to be visible on dark backgrounds as well.
I'd like to maintain the transparency feel. I do not want to use an outline because it wold be the only outlined item on the site.
Edit: I ended up doing a combination of the suggestions. I added a white glow and I added a semi transparent white circle behind the black one which filled in the triangle and had the same effect as adding the grey. Thanks fo ryour help with this.