For iteration #2: I added Hex color to RGB to the conversion app page converter.
This will take the 6-digit hex color only accepting 0-9 and A-F. Then it will convert the Hex to RGB with commas between the 3 color grouping.
For the RGB to Hex the user will need to include the commas between the color groupings. This will convert it over to the Hex coding, making the A-F in caps. While it doesn’t matter in the hex code if it’s upper or lowercase I’ve always preferred to have it in uppercase making it a bit quicker to spot in the code. The RGB separated by commas since this is how it’s expected in most programs.
Looking up the formulas for the conversion took some time, found a few different ones but after some trials got one that matched the sample version.
For testing I used: https://en.wikipedia.org/wiki/Web_colors
In my testing I used about 20 colors or more to test the conversions between the two. About 10 for hex to see if the RGB is correct then reversed it for other colors. I used different color types like close to white, reds, blues, a green, and a dark gray.