Differential speckle interferometry has been applied to data obtained using the fully phased six-mirror aperture of the Multiple Mirror Telescope. Wavelength-dependent differences in the appearance of a stellar object are derived from simultaneous observations at two distinct wavebands. The supergiant star Alpha Orionis was observed this way to investigate its appearance in hydrogen-alpha emission. Data reduction consists of a frame-by-frame weighted deconvolution. An inherent Wiener-type filtering must be removed in order to preserve high spatial frequency information. Results for Alpha Orionis are compared to similar results for the unresolved source Gamma Orionis.