#4169e1, RGB (65, 105, 225)
Royal Blue was originally deep blue, darker than the color we think of as Royal Blue today.
In the 1980s when the original set of named web colors was created it was the brighter version that was included, and that is the one that we typically call Royal Blue today. This color is known as RoyalBlue in the named HTML colors.
Royal Blue has a hex value of #4169e1 which gives it an RGB value of (65, 105, 225). That makes it approximately 25% red, 41% green, and 88% blue. On the CYMK color model Royal Blue is 71 cyan, 0 yellow, 53 magenta, and 12 black. It is also 225° hue, 73% saturation, and 57% lightness on the HSL color model and 225° hue, 71% saturation, and 88% value on the HSV color model. Royal Blue is not a Pantone color, but it is close to Pantone color 814. Royal Blue is not a DIC color, but it is close to DIC 183s*. Royal Blue is not a web safe color, but it is close to #3366cc.