Question

We all know that when we select a text portion in browser, its background color changed to blue. Is it a way to change this color through CSS or JavaScript?

Answer 1

Yes: you can use the ::selection and ::-moz-selection pseudo-elements (MDN), which allows you to specify the foreground and background colours of selected content. This will work in all major browsers except IE < 9, for which there is no alternative.

::selection {
    background: pink;
    color: yellow;
}

::-moz-selection {
    background: pink;
    color: yellow;
}