Color problems on my TV- degaussing?

Ok, so lately there has been a problem with my tv. It has weird colors coming from the sides, but sometimes it's all over the screen. It seems everything is either green, red or purple, but whatever the case, not the color it should be. I've tried dusting with one of those air can things, but it didn't help much.

I've read some and it sounds like the problem is that it needs to be degaussed (new to me), but I really don't know where to find a degaussing coil or wand. Actual stores I mean. Not online, what stores actually carry them?

Or could this be another problem, I don't want to buy one of those and waste the money if it's something else.

Thank you.