How to correct a background map showing through map when displayed via the Mapping Service in Spectrum 9

Products affected: Spectrum 9™
Location Intelligence Module
Windows Server 2012

Issue

When displaying a raster image via the MappingService in Spectrum 9 Location Intelligence Module any background image shows throw as if parts were transparent, as shown below.

User-added image

Cause

In Spectrum we have default style concept, so if no style is defined we apply the default style.
 
The default style for rasters is currently coded to make white pixels transparent. Ideally the default style but should match whatever MapInfo Pro does when no style is applied.
 
Having a black object behind a raster would require specifying black pixels to be transparent. Alternatively, it is also possible to remove all transparency which would seem like a more appropriate workaround to this specific scenario.

Resolution

UPDATED: August 28, 2017
In both cases this is fixed by editing the named map to include the a style override on the background layer, for example:
 
<FeatureStyleModifierThemeList>
<FeatureStyleOverrideTheme id="id6" name="Style Override" alias="Style Override id6">
<RasterStyle contrast="0.5" brightness="0.5" opacity="1" grayscale="false" transparent="false" transparent-color="rgb(0,0,0)"/>
</FeatureStyleOverrideTheme>
</FeatureStyleModifierThemeList>
 
To help describe there is an attached copy of the named map used to test this. Open this in a text editor to see that the named map (10ksub_with_background_and_StyleOverride) is made up of _10ksub (ecw raster layer) and background (simple black coloured region object layer that is placed behind the raster).
 
From lines 34 to 38 examine the style override using the transparent="false" parameter which displays this raster correctly. When this is applied this will resolve the issue as seen in the screenshot:

User-added image
This is only a workaround and identified as a defect to be fixed in a future patch/release (defect: MID-15874).