Understanding CSS
Think inside the BOX

1. there is an invisible box around every HTML element.
2. CSS allows you to create rules that control the way that each individual box.
3. CSS Associates Style rules with HTML elements.
4. CSS Properties Affect How Elements Are Displayed.
Colors

what is Foreground Color for CSS
The color property allows you to specify the color of text inside an element. You can specify any color in CSS in one of three ways:
1. Red-Green-Blue (RGB) values.
2. HEX Codes.
3. Color Names.
—
what is Background Color for CSS
CSS treats each HTML element as if it appears in a box, and the background-color property sets the color of the background for that box.
You can specify your choice of background color in the same three ways you can specify foreground colors: RGB values, HEX and Color Names.
See the Picture below to know more about colors:
