Alpha using Hexadecimal color code

I have been going through the HTML and CSS course where I saw that you need to use rgb() or hsl() codes in CSS so you can apply alpha to color.
That is possible to achieve with hexadecimal as well (at least on google chrome) using #rrggbbaa order where ‘aa’ represents alpha. 00 is equivalent to 0% and ff to 100%.
Just posting this if anyone is curious.

PS. Hi! I am Miran and I am new here. (edit: name}