There are 3 sets of primary colors. The colors cyan, magenta, and yellow are commonly termed the complementary colors because each complements one of the primary colors in a white light mixture. Yellow (red plus green) is the complement of blue because when the two colors are added together white light is produced. Likewise, cyan (green plus blue) is the complement of red, and magenta (red plus blue) is the complement of green light. The complementary colors (cyan, yellow, and magenta) are also commonly referred to as the primary subtractive colors because each can be formed by subtracting one of the primary additives (red, green, and blue) fr om white light. Mixing them in different amounts produces varying numbers of colors. Ever wonder what you get when you mix, say, sky blue [color code 6074F2] and dark yellow [color code 808000] in terms of light? It turns out that you end up with a greyish color with a small touch of cyan, or color code 707A79. Wh ere to get these color codes? To find out RGB color value, use Paint program included into standard Windows package.
• Launch Paint; open an image containing the needed color
• Go to Instruments panel; select Picker instrument
• Click the needed color to select it. This color will appear in the palette as brush color
• In the “Colors” section of the main menu, select “Edit Colors” menu item
• Press “Define custom colors” button. The window will expand to present the color you have selected as well as its RGB numeric values for every channel.
If you have selected pure red color, the values will be: red =255 green=0 blue=0. You will need these numeric color codes to change colors via the command-line.