Created attachment 8658019 [details] Capture.PNG User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0 Build ID: 20150826023504 Steps to reproduce: I simply updated to Windows 10 and all of a sudden some of the fonts on websites are white with blackout lines. Making them hard to read. Actual results: Some of the fonts on websites are white with blackout lines. Making them hard to read. Expected results: The update to Windows 10 for Firefox should've caused no font issues. Refreshing or reinstalling firefox doesn't fix this problem
Can you paste the contents of your about:support Graphics section?
This looks like bug 1185812; see further details there.