What happens if you position it somewhere away from the Playbase? Have you tried that, and hence your concern it’s the Playbase causing the issue? Or, what display settings are you trying for the tv?

Thanks for reply.

I can’t position it away from the Playbase for practical reasons.

I’m just checking whether any magnets in the Playbase might affect the TV.  It’s not patches of colour rather an overall slight tint.

I didn’t mean as a permanent placement: just to see if the tint goes away. 
 

My Playbase is very close to my Sony tv with no issues.
 

The Playbase was designed to allow TVs of appropriate size to sit directly onto it, so I’d be very surprised if it’s causing an issue. 

Not unless something is wrong with the Playbase.  Electronics meant to used near displays have shielding to prevent any interference.

Magnets impacted old tube and electron gun TVs by deflecting the beam. Even then the distortion was clearly stronger closer to the magnet than further away.

So with no beam to deflecting it is unlikely. With the entire screen impacted evenless likely.

Grab a magnet,maybe off the fridge and see if it impacts the screen.

I'd look for a TV color-balance setting, might be set to too warm a color temperature for your taste. We flip ours for day and night viewing, mostly for the blue light reduction warmer settings offer over the daylight/ cooler ones for evening viewing.