It would be great if Wix adds a color Picker tool into the editor.
It would be way easier to get more harmony in Background, Pictures and Fonts if you could just use the color picker. 
I strongly support this suggestion
If you’re using Wix Studio, we have a series of Editor Add-ons that provide additional functionality like this - on being Color Selection - About the Wix Studio Add-on Tools | Help Center | Wix.com