Colors and backgrounds
https://www.w3.org/TR/CSS2/colors.html#propdef-background-attachmentCSS properties allow authors to specify the foreground color and background of an element. Backgrounds may be colors or images. Background properties allow authors to position a background image, repeat it, and declare whether it should be fixed with respect to the viewport or scrolled along with the document.. See the section on color units for the syntax of valid color …