What is a selector?
Selectors are used to select elements to style with properties.
What is a property?
A property is something inside of a selector that you use to style something, for example, you could change the colour of some text.
What is a property value?
This is where you would change the appearance of an element, for example, you could change the size of the text to 22px.
In the HEX value it would be:
In the HSLA value it would be:
With the RGBa value you can change the opacity of a color so rgb(24, 244, 0) with an opacity of 50% would look like:
To add a background colour with the colour values above you will need to add the background-color: ; attribute inside of the open brace and close brace. Then you can add your colour value between the colon and semi-colon.
As well as being able to customize the background colour of a HTML element, you can also change the colours of borders, text, shadows etc.