  It has long been known that the post-core-collapse globular cluster M30 has a
bluer-inward color gradient, and recent work suggests that the central
deficiency of bright red giants does not fully account for this gradient. This
study uses Hubble Space Telescope WFPC2 images in the F439W and F555W bands,
along with ground-based CCD images with a wider field of view for normalization
of the non-cluster background contribution, and finds \Delta(B-V) ~ +0.3 mag
for the overall cluster starlight over the range r = 2" to >~ 1'. The slope of
the color profile is: \Delta(B-V)/\Delta\log(r) = 0.20 +/- 0.07 mag dex^{-1}.
We explore various algorithms for artificially redistributing the light of
bright red giants and horizontal branch stars uniformly across the cluster. The
traditional method of redistribution in proportion to the cluster brightness
profile is shown to be inaccurate. There is no significant residual color
gradient in M30 after proper uniform redistribution of all bright evolved
stars; thus the color gradient in M30's central region appears to be due
entirely to post-main-sequence stars. Two classes of plausible dynamical
models, Fokker-Planck and multimass King models, are combined with theoretical
stellar isochrones from Bergbusch & VandenBerg (1992) and from D'Antona et al.
to quantify the effect of mass segregation of main sequence stars. In all
cases, mass segregation of main sequence stars results in \Delta(B-V) ~ -0.06
to +0.02 mag over the range r = 20" - 80"; this is consistent with M30's
residual color gradient within measurement error. The observed fraction of
evolved star light in the B and V bands agrees with the corresponding model
predictions at small radii but drops below it for r >~ 20".
