Both HEX and RGBA are ways of defining colors in code like HTML and CSS.
Generally HEX is easier to use, as it is shorter. However in some cases it is better to use RGBA, because you can also define the opacity. This can be handy if you want to set a lighter or more subtle background color.
- The color code for One.com green in HEX looks like this: #77a345
- The same color in RGBA looks like this: (119, 163, 69)
- If you want to add 50% opacity to the RGBA color it looks like this: (119, 163, 69, 0.5)
There are a lot of sites on the internet to help you pick a color or convert it from HEX to RGBA, or the other way around.