How to convert “background-color” to rgb() format?

Question

Here is my problem:

I want to change the opacity of background-color of one of the elements on my page. in order to do this I need to first convert the color to rgb() fo

Answer 1

Use window.getComputedStyle(elem, null).getPropertyValue("background-color"); to get the background-color string. Then, check if it's in a desired format.

• rgb(n, n, n)
• Others, such as hsl, rgba, hsla, ... convert these using an easy-to-find algorithm
• Color names: Create a map of colornames-to-rgb (such as: var name2rgb = {red: "rgb(255, 0, 0)"};)

A list of color names can be found on the web. Visit this site for a list of colornames (which is probably not complete).