An application I wrote in Visual Basic 6 when I was back in college (around 2003) as part of an assignment to return the Hex and R,G,B of a color.
It's fairly straightforward. The horizonal scrollbars update the background color as well as the Hex and R,G,B values.
You can also change the number in the textbox to the side if you want to quickly find out the Hex code.
Copy simply copies the Hex to the clipboard.