Extracts the blue value from a color, scaled to match current colorMode(). The value is always returned as a float, so be careful not to assign it to an int value.

The blue() function is easy to use and understand, but it is slower than a technique called bit masking. When working in colorMode(RGB, 255), you can achieve the same results as blue() but with greater speed by using a bit mask to remove the other color components. For example, the following two lines of code are equivalent means of getting the blue value of the color value c:

 float b1 = blue(c); // Simpler, but slower to calculate
 float b2 = c & 0xFF; // Very fast to calculate 


  • size(400,400);
    color c = color(175, 100, 220);  // Define color 'c'
    fill(c);  // Use color variable 'c' as fill color
    rect(60, 80, 140, 240);  // Draw left rectangle
    float blueValue = blue(c);  // Get blue in 'c'
    println(blueValue);  // Prints "220.0"
    fill(0, 0, blueValue);  // Use 'blueValue' in new fill
    rect(200, 80, 140, 240);  // Draw right rectangle
    Image output for example 1


  • blue(rgb)


  • rgb(int)any value of the color datatype


  • float