In the Houdini colorbar HDA under "color options", set the menus like this...
Details:
png file
/svs/share/houdini/cbars/images/png/ozone_asia_vol.png
tex file
/svs/share/houdini/cbars/images/tex/ozone_asia_vol.tex
definition
/svs/share/houdini/cbars/definitions/svs/ozone_asia_vol.csv
credit
unknown
reference
unknown