Make following:

-> Load 3D gray image
-> Set color to e.g. blue
-> Now go to porperties tab and change "Use color" to false so that the lookuptable is used
-> The colors in 2d vis are different than those in 3D planes

Solution:

change on mitk::Geometry2DDataVtkMapper3D.cpp on line 759:

if(useColor)
{

imageActor->GetProperty()->SetColor( rgb[0], rgb[1], rgb[2] );

}
else
{

imageActor->GetProperty()->SetColor( 1, 1, 1 );

}

I am not allowed to check in.....