An example system for thermal energy determination can include a first controller comprising a processor and a non-transitory machine-readable medium (MRM) communicatively coupled to the processor. The non-transitory MRM can include instructions executable by the processor to cause the processor to receive relative humidity information of an environment of a thermal printing device, determine a colormap to a print media of the thermal printing device based on the relative humidity, and determine a particular thermal energy to apply to the print media based on the determined colormap.