There is a predefined set of colors in the blocks palette
As pictured below, the easiest way to set a specific color is using a text block with the syntax rgba(r,g,b,a)
If you want to select specific colors, use the RGB block below
Strangely, you can also create a color by blending two together
or you can choose one at random
A popular alternative to setting RGB color is to set Hue, Saturation and Value colors with the block below
