RGB
Purpose 
Returns an integer number from 0 to 16777215 obtained by combining the red, green, and blue values (each ranging from 0 to 255) to represent a color.
Format 
RGB(red;green;blue)
Parameters 
red - any numeric expression or numeric field containing a value ranging from 0 to 255
green - any numeric expression or numeric field containing a value ranging from 0 to 255
blue - any numeric expression or numeric field containing a value ranging from 0 to 255
Data type returned 
number
Originated in 
FileMaker Pro 7.0
Description 
Numbers returned by this function can be passed as the color parameter in the TextColor or TextColorRemove functions. The RGB function uses the following formula to calculate the result:
red * 2562 + green * 256 + blue
where 2562 = 65536
 
Tip  To determine the RGB value of a color, in Layout mode, click the Fill color palette in the formatting bar and choose Other Color. In OS X, select the Color Sliders tab. Values are shown for each of the basic colors.
Examples 
RGB(255;0;0) returns 16711680 representing red.
RGB(0;255;0) returns 65280 representing green.
RGB(0;0;255) returns 255 representing blue.
RGB(0;0;0) returns 0 representing black.
RGB(255;255;255) returns 16777215 representing white.
Using a table with text fields FirstName and LastName, specify the following auto-enter calculation for a third field called FullName that displays FirstName in orange and LastName in purple:
TextColor(FirstName;RGB(255;165;0)) &" "& TextColor(LastName;RGB(160;32;240))
Related topics 
Functions reference (category list)
Functions reference (alphabetical list)
About formulas
About functions
Defining calculation fields
Using operators in formulas