Solution - Displaying Mapserver raster in ArcMap gives 256 colours

[POWER Brendan]

Thanks to Ed McNierney, Frank Warmerdam and Bart van den Eijnden - it
seems that ArcMap is requesting a PNG from Mapserver - which then
defaults to 256 colours.  By changing the OUTPUTFORMAT IMAGEMODE
definition for png to RGBA, it has resolved the issue.  In the end an
easier solution to than I thought it would be.
Thanks again guys for the quick response.
Regards,

Brendan Power
Manager GIS
Fire & Emergency Services Authority of WA

address:	480 Hay Street Perth WA 6000
postal:		Po Box P1174 Perth WA 6844

phone:	9323 9351	mobile:	0417 918 809
fax: 	9323 9384	web: 		www.fesa.wa.gov.au