NOTE: IT IS BEST TO VIEW THESE IMAGES AT 16K COLORS OR HIGHER

Color separation (chromatic abberation) happens to some degree with all refractive devices. It is inherent in their design (this is how a prism separates light into color spectrum and how a rainbow works.) Lens magnify by refracting light. Unfortunately, not all wave lengthes of light (colors) refract the same amount through the same substance. This separation becomes more pronounced toward the edges of large aperature lens. That is why photographers like to stop down their lenses somewhat to "sharpen" them. The short tube refractor is a very fast scope f/5 as telescopes go and therefore generates more of this effect. More expensive (as in, much more expensive) refractor scopes use exotic materials such as Flourite and Vandium which reduce the difference between the refractions of the different colors. Alternatively, there are reflective scopes like the Newtonian that don't suffer from this effect. These scopes require obstructions in there field of view, though which causes its own problems.

Color separation is most noticable on white objects because they are made up of a wider spectrum of wavelengthes. Purple is the most apparent color because its wavelength gets refracted the most. On this shot of a white daisy you can see a very pronounced purple halo around the white petals.

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