Each pixel represents a starting value for Newton's iteration. If after 20 iterations, Newton's Method has not located a zero of f(x), then the pixel is colored black. If Newton's Method converges to -1 the pixel is colored blue, to (1+sqrt(3)i)/2 the pixel is colored red, and to (1-sqrt(3)i)/2 the pixel is colored green. Real values between -2 and 2 and imaginary values between -2 and 2 are shown.