Does anyone else obsessively comb old episodes, hoping to pick up on foreshadowing or ~ hidden meaning ~? (Blame my grade ten / eleven English teacher. Now I can't turn it off.)
Different colours usually mean different things - blue / white for angels, red / black for demons. Early on, bright colours were often a sign of Something's Not Kosher, considering how the show used to feature a dark, washed out filter (which they seemed to have kicked around season seven. I miss the creepy atmosphere.)
One thing I noticed specifically is that yellow tends to also pop up when Things Aren't Quite Right - Sam in particular has a couple yellow shirts that first caught my eye. ("What is and What Should Never Be", "Changing Channels" / most funny spell eps. There is a lot of yellow on both boys in "It's a Terrible Life".)
I wrote a whole meta (more of a list since I'm too lazy and scatterbrained to actually write / post meta) on it and I like to use it as a conversation starter because I think it's an interesting topic. Do you guys notice meanings attached to any other colours?