In the Houdini colorbar HDA under "color options", set the menus like this...


Details:

png file /svs/share/houdini/cbars/images/png/GLDAS_Underground_Soil_Moisture_Monthly.png
tex file /svs/share/houdini/cbars/images/tex/GLDAS_Underground_Soil_Moisture_Monthly.tex
definition /svs/share/houdini/cbars/definitions/gibs/GLDAS_Underground_Soil_Moisture_Monthly.xml
credit unknown
reference https://gibs.earthdata.nasa.gov/colormaps/v1.0/