Player variable in JSON [duplicate]

I'm trying to make a minigame where you have different kits. You step on a pressure plate and get all your armor and effects added. That's all working fine. I'm trying to make it so it places a sign above the pressure plate saying "TAKEN" "BY" "[PLAYERWHOHASTHATKIT]" In bold dark red Is this possible? I've tried /blockdata ~ ~-1 ~ {"Text3":"@p"}with all the other text I want. Is this possible?

You must use the selector tag of the text component to resolve a selector into a name. It replaces text, translate, and score tags at that depth (such that you cannot use selector and text at the same time).

Example:

/blockdata ~ ~-1 ~ {"Text3":"{\"selector\":\"@p\",\"color\":\"dark_red\"}"}