## Specifying colors

You specify a color by specifying a number that represents the color. You can specify the number explicitly or by using an expression that includes the RGB (r, g, b) function.

For the numbers and expressions that specify common colors, see Table: Numbers and expressions for common colors.

How the number is calculated

The formula for combining color values into a number is:

`red + 256*green + 256*256*blue`

where the amount of each primary color (red, green, and blue) is specified as a value from 0 to 255.

The RGB function calculates the number from the amounts of red, green, and blue specified.

Sample numeric calculation

To create cyan, you use blue and green, but no red. If you wanted to create the most saturated (bright) cyan, you would use maximum amounts of blue and green in the formula, which is indicated by the number 255 for each. The following statements show the calculation:

```red + 256*green + 256*256*blue
0 + 256*255 + 256*256*255
0 + 65280 + 16711680
16776960```

Sample expression using the RGB function

The following expression specifies the brightest cyan:

`RGB (0,255,255)`

Notice that the expression specifies the maximum for green and blue (255) and 0 for red. The expression returns the value 16776960. To specify cyan, entering the expression RGB(0, 255, 255) is the same as entering the number 16776960.

Numbers and expressions to enter for the common colors

The following table  shows the numbers and expressions to enter for some common colors. The number and expression for a color are equivalent. You can use either.

Color

Expression to enter

Number to enter

How the number is calculated

Black

RGB (0, 0, 0)

0

0 (no color)

Blue

RGB (0, 0, 255)

16711680

256*256*255 (blue only)

Cyan

RGB (0, 255, 255)

16776960

256*255 + 256*256*255 (green and blue)

Dark Green

RGB (0, 128, 0)

32768

256*128 (green only)

Green

RGB (0, 255, 0)

65280

256*255 (green only)

Light Gray

RGB (192, 192, 192)

12632256

192 + 256*192 + 256*256*192

(some red, green, and blue in equal amounts)

Lighter Gray

RGB (224, 224, 224)

14737632

224 + 256*224 + 256*256*224

(some red, green, and blue in equal amounts)

Lightest Gray

RGB (240, 240, 240)

15790320

240 + 256*240 + 256*256*240

(some red, green, and blue in equal amounts)

Magenta

RGB (255, 0, 255)

16711935

255 + 256*256*255 (red and blue)

Red

RGB (255, 0, 0)

255

255 (red only)

White

RGB (255, 255, 255)

16777215

255 + 256*255 + 256*256*255 (red, green, and blue in equal amounts at the maximum of 255)

Yellow

RGB (255, 255, 0)

65535

255 + 256*255 (red and green)