Error “invalid value” when customizing css

When I go to Appearance –> Customize –> Theme Options –> Theme General Options and simply try to change some colors on my website I get an error that says “invalid value”. All I am doing is pasting some different hex colors into previous hex color locations within the custom css and when I go to save and publish I get the above error.

If someone knows what I’m doing wrong or a fix I’d greatly appreciate it. Thanks!