An accepted answer with three downvotes (now deleted) appeared "faded" but when my mouse pointer hovered over the answer, the text appeared normal.
What does the faded text signify?
Answers with a total score of -3 or less automatically render faded until you tickle them with your mouse. That's independent of the accepted thingy. I think the reason is to visually mark them as not exactly useful at a glance.
Disclaimer: I couldn't find an official source or help page for this behaviour, so this is just my personal observation and experience.