We present spectroscopic evidence of the preferential solvation and penetration of the cosolvents benzene and methylene chloride into the surfactant tail regions of AOT reverse micelles in supercritical ethane. The micropolarities on both sides of the AOT surfactant interface were investigated using the UV-vis absorption probes phenol blue and methyl orange. Phenol blue was identified to reside in the surfactant tail region of the AOT reverse micelles, and its wavelength of maximum absorption remained sensitive to property changes in the ethane continuous phase. Furthermore, the preferential penetration of cosolvents benzene and methylene chloride was observed as evidenced by a synergistic effect (enhanced red shift) on the phenol blue absorption spectra over the experimental pressure range. Studies with the probe methyl orange, which resides in the reverse micelle core, further showed that, while the composition of benzene is enhanced in the surfactant tail region, benzene did not penetrate the reverse micelle core.