Colour problems on Panasonic Viera TH-42PX60B. Blue too strong through HDMI?

I have a Panasonic Viera TH-42PX60B plasma TV, which has a tendency to over-enhance blue colours when viewing any thing via the HDMI ports. This is apparent when using either HDMI port, with different sources (Panasonic DVD player and Sony Blu-ray player) and different HDMI cables. The standard definition picture via scart connection has natural looking colours, from Sky+ box and analogue and digital built in tuners.
I've tried normal settings such as cool/warm/normal, colour management etc, but to no avail.
Is there a service menu I can access to adjust the blue level?