Excel: Using either Red, Green, Blue numbers or RGB Code to fill a cell

Question

It's been awhile since I did something like this so I am struggling and could use the help. I currently have a spreadsheet where I have listed the Red, Green, and Blue values of a colour, currently I can Fill a cell with that colour if I open the menu and do custom colour. I'm wondering if there is a way that this can be done automatically?

Here is an example of what I am wanting with some blank colour cells so you can see what I am referring too:

Any help would be appreciated

Thank you!