Visualize 1 band raster DEM in RGB

Hi everyone,

I have a very basic (I guess) issue that I can't deal with nor find an appropriate tutorial or answer on the web... I have a 1 band Geotiff that comes from a substraction between two Digital Elevation Models (bathymetric survey). I manage to give a value to nodata (RasterBandNodataSetter) and remove the nodata identifier (RasterBandNodataRemover). So the Geotiff I'm working with as no nodata.

I want to associate color (chosen or by default) to different ranges of value, just for visualization of the result. I can do it with any GIS software (like ArcGIS) but couldn't manage to do it with FME. I tried to connect a RasterPaletteGenerator to the Geotiff Reader but I get a translation terminated with the rejection code 'INVALID_RASTER_BAND'.

As I have no idea of the problem and where to start to manipulate palette and raster band, any help or links to tutorial or web pages would be greatly appreciated.

Please find attached the Geotiff I'm talking about.

Thanks you

Jérémie