Hi Aaron,
Sorry for the delay in getting back at this.
We have analyzed your requirement, and we like to inform you as for now we have don't have support for showing different colors in 3d Surface chart and there is already a feature request regarding this in our database. Regarding the heat map the size of the plot is determined internally and this is the default behavior.
Please let us know if you have any concerns.
Thanks,
Michael Prabhu.