There are 4 CPT files. Color gradient is based on
this web. The color steps work pretty well I guess
DownloadInstallCreate
interpolators folder in Locus > data and download the files to the interpolators folder.
ThemesLowland.cptRange -50 to 1000 m ASL (white color over 1000 m) / 25 m and 50m steps
Highland.cptRange 100 to 2000 m ASL (white color over 2000 m) / 50m and 100 m steps
Alps.cptRange 400 to 4500 m ASL (white color over it) / 100 and 200 m steps
Mountains.cptRange 1000 to 6500 m ASL (white color over it) / 200 and 250 m steps
ScreenshotsLowland theme - Central Bohemian Uplands - Highest peak about 800 m ASL
Highlandtheme - Krkonose mountains - Highest peak 1602 m ASL
Alps theme - Austrian Alps
Mountains theme - Nepal
Highland vs Alps theme - High and Low Tatras in Slovakia

Edit: modiy altitude ranges and steps