Maybe I am just a dumba** but I don't get it

Maybe somebody can help me. When I post a write a new entry I change the font color to blue. It shows blue on the preview but when it loads on the blog it's freakin' green What gives ? I have gone back and recolored it and recolored it but it keeps turning green. Not for every post mind you just for some of them. And some times it's only certain words that show up green in an otherwise blue post. I just don't get it.......