基于数据库的PHP动态CSS

found a couple answers here on StackOverflow and used them as my models, but I must be missing something. I'm trying to set a couple of background colors dynamically in CSS based on what is in my database, but it's not working - when I check Inspect Element in Chrome, background-color has a line through it and a warning mark for 'Invalid property value'.found a couple answers here on StackOverflow an