Select color

From the Color List

• In the Select Color dialog box, select a color from the Color list.
  The right part of the color box shows the current color. The left part shows the previous color.

From the color selector

• Drag the marker around the wheel to define the hue.
• Drag the marker horizontally in the square to define the saturation level.
• Drag the marker vertically in the square to define the brightness value.
  

From the HSV and RGB boxes

• To select an red/green/blue (RGB) color, type RGB values in the R, G, and B boxes.
• To select an hue/saturation/brightness value (HSV) color, type values in the Hue, Sat, and Val boxes.
  When the Sat value is 0, the Hue value has no effect.

Customize the color list

1. Edit the colors.txt file in the Rhino support folder in a text editor.
2. Add your color definitions in the format of <Name>,<Red>,<Green>,<Blue>.
   The colors.txt file has to contain at least two color definitions. Otherwise, Rhino will ignore the colors.txt and use its internal color list.
   
3. Start a line with ";" or "//" to add a comment or comment out a color definition.
4. Restart Rhino to load the new color list.

My Color 1,105,105,105 My Color 2,130,0,0 //Dark Red My Color 3,0,0,130 ;Dark Blue My Color 4,0,135,130
The color definitions.	The result.