[Aviator168]

Can the color arcs be set in the units? Is the redline adjusted for altitude? Just curious.

 

[N941WR]

Are you asking about an EFIS or EMS?

Most EMS's are adjustable and the color moves with the numbers you put in.

 

[DGlaeser]

EFIS settings

I have a GRT Sport, and all the EFIS's I've seen have the 'arc' airspeeds defined by user settings. The VNE (red line) speed does NOT change with Altitude - the markings are just like a steam gauge ASI.
I haven't even seen an alert or warning setting for TAS - which would serve the purpose of an altitude corrected VNE. That would be an interesting feature to add...

 

[Aviator168]

I thought every manufacturer have done that by now. Guess not.