I'm using Geoserver (2.1) to load raster data with the Imagemosaic plugin and then using Geowebcache to cut this data into tiles across the full coverage of the British National Grid. However the data does not extend to all areas of this extent and in these areas I get black background where there is no data.
To resolve this I loaded a vector background which serves as a blue sea background for areas where the raster data does not extend to. However where the vector and raster areas meet I am still seeing sections of black no data background (even though the vector data covers all areas where the raster data does not and is behind it in the layer group).
I've tried setting both the InputTransparentColour and the OutputTransparentColour options to black which does make these black areas disappear, however it also causes the black text on the raster mapping to become transparent as well.
Does anyone know of any other ways to change this background colour without effecting the raster data itself? Or why these black areas might still be appearing even though there is vector data there that should be displayed?