You can change the values by clicking and dragging the mouse inside the bars, or typing a numerical value in the text fields beside the bars and pressing Tab . The color wheel shows a horizontal slice of the double cone discussed above. Changing lightness changes which slice of the cone you are looking at. Although the range of colors you can create with RGB is the same as with HLS, the RGB model is much less intuitive and it poses difficulties for color synthesis. The RGB color space is modeled by a three-dimensional cartesian coordinate system, with three mutually perpendicular axes.
Red values vary along one axis, green along another, and blue along the third.
Each value of R, G, and B can range from 0 to 1. The RGB color space thus forms a color cube . The color sliders control the intensity values of red, green, and blue, and are used like the HLS sliders. The square color patch at the upper right corner shows a red slice of the RGB color cube. That is, as you vary the red slider, the color patch will display the green-blue plane for that value of red.