  We present a compilation and study of DENIS, 2MASS, ISOGAL, MSX and IRAS
1--25 micron photometry for a sample of 441 late-type stars in the inner
Galaxy, which we previously searched for 86 GHz SiO maser emission (Messineo et
al.2002). The comparison of the DENIS and 2MASS J and Ks magnitudes shows that
most of the SiO targets are indeed variable stars. The MSX colours and the IRAS
[12]-[25] colour of our SiO targets are consistent with those of Mira type
stars with dust silicate feature at 9.7 micron feature in emission, indicating
only a moderate mass-loss rate.
