A new type of affine moment invariants for color images is proposed in this paper. The traditional affine moment invariants can be computed on each color channel separately, yet when the channels are transformed together, by the same affine transform, additional invariants can be computed. They have low order and therefore high robustness to noise. The new invariants are compared with another set of invariants for color images using second powers of the image function. The basic properties of the new features are tested on real images in a numerical experiment.