Some Words Don't Show/Are Half Grey

Some words (Mainly what I think is "Cancel") don't show up or are half grey. This only started when I downloaded the 1.8 update. I've already tried uninstalling (deleting the .minecraft file and backing up the saves and resource packs), then re-installing minecraft but it made no difference. The issue's bearable, but a little annoying.

What I expected to happen was...:
All words show and are displayed with white letters.

What actually happened was...:
Some words in different areas of the game don't show or are half grey.

(Sorry if this counts as two issues.)