We all use colours. Maybe you are a seasoned front end developer or designer, your custom terminal colour scheme is something to behold, or perhaps your small child (or you) is currently going through a finger painting stage. Regardless of what part of tech you work in, you have encountered a situation when you've had to select some colours. The question is, when you pick a colour on a colour wheel or type in a hex or RGB code, how does that colour actually appear on the screen? Come and learn about the Computer Science of colour with me. In this talk, we're going to dig deeper into hex codes. What do they mean, how and why do they get converted to RGB codes, and how does a computer use that to generate a colour we can see? We'll unpack it all by learning binary, enjoying a #throwback to mixing paint in kindergarten, and taking a much closer look at the human eye. You will leave this talk with a whole new appreciation and understanding for the science behind something as simple as colour, something you have likely never thought twice about. This talk is not just for designers and front end developers, there is something interesting for everyone to learn here.