[Affected versions]: Nightly 54.0a1, Nightly 53.0a1 and Firefox 51.0.1 [Affected platforms]: All platforms: Windows 10 x 64 [Steps to reproduce]: 1. Activate a high contrast theme. - Windows: Go to Personalize> Themes> Theme Settings and activate a High Contrast Theme. 2. Launch Nightly 54.0a1 with a new profile and then open this link https://www.amazon.com/gp/browse.html?node=12774562011. 3. Observe the video after hovering on it. [Expected result]: The video is correctly displayed. [Actual result]: In high contrast themes the video becomes black when hovering over it.

Thanks for the bug report! One question: (In reply to Hani Yacoub from comment #0) > [Affected versions]: > Nightly 54.0a1, Nightly 53.0a1 and Firefox 51.0.1 Are you sure all those versions are affected? If Firefox 51.0.1 is affected, then this shouldn't be marked as blocking bug 1271765 (i.e. it wasn't caused by that bug), because that bug's changes are new in Firefox 53. (Not that that makes this bug any less bad -- just want to be sure we're tracking it correctly.)

Yes, I am sure that all those versions are affected. You are absolutely right I shouldn't have marked that bug as a blocker, i will remove it. Thanks.

Looking more closely: (1) The video shown in the screenshot is not using our provided video/audio controls. (So, this is the wrong component for this bug.) (2) The video-blackening isn't from controls anyway -- it comes from some partially-transparent "dimming" overlay that Amazon seems to place on top of the video, when the user hovers it. (And in high contrast mode, we render that dimming div as fully-opaque, I guess.) (3) The exact same thing happens in Edge as well (in High Contrast mode) There might be something we could fix in High Contrast Mode implementation here, but maybe not given that we're consistent with Edge. So I think this is probably a Tech Evangelism issue -- i.e. to the extent that there's a bug here, it's that Amazon's "dimming" overlay doesn't play well with Firefox/Edge's high-contrast rendering. (I don't know enough about High Contrast mode to have any concrete suggestions, but perhaps someone else will.)

(FWIW, when poking at this bug, I did run into an issue with our *actual* video controls, too, and I spun off bug 1339512 for that.)

Mass wontfix for bugs affecting firefox 52.