  Based on the colour measurements from a multi-band, multi-component 2D
decomposition's of S0 and spiral galaxies using SDSS images, we found that bars
are bluer in S0 galaxies compared to the spiral galaxies. Most of the S0s in
our sample have stellar masses $\sim L_{*}$ galaxies. The environment might
have played an important role as most of the S0s with bluer bars are in the
intermediate-density environment. The possibility of minor mergers and tidal
interactions which occurs frequently in the intermediate-density environment
might have caused either a bar to form and/or induce star formation in the
barred region of S0 galaxies. The underlying discs show the usual behaviour
being redder in S0s compared to spiral galaxies while the bulges are red and
old for both S0 and spiral galaxies. The finding of bluer bars in S0 galaxies
is a puzzling issue and poses an interesting question at numerical and
theoretical studies most of which shows that the bars are long-lived structures
with old stellar populations.
