Color scheme and the colorblind
(On a laptop, to someone who is red/green color-blind.)
The "answered" checkmark should take on a distinctly different color from the up/down arrows, to avoid confusion.
Rather hackish, makes it into a dark green box:
Put this in a bookmarklet (create a new bookmark with this code as the location), and click it on every phy.SE answer page.
If you don't want to click the bookmarklet on every page, then you may want to set it up as a userscript. Copy this to notepad:
prominentaccept.user.js or something. Drag-drop this file into your browser. You will need to install Greasemonkey on Firefox. On chrome, it will prompt you and work straight out-of-the-box on physics.SE and meta.physics.SE