Hi
As far as I'm aware Hornby havent altered anything around CV settings regardless of the coloured dots. Only CVs 1, 3, 4 & 29 are supported. Therefore it appears CV2 cannot be adjusted. Hornby R8215 Decoder Manual
Bachmann 553 decoders can have CV2 adjusted. Bachmann decoder manual
As far as I'm aware Hornby havent altered anything around CV settings regardless of the coloured dots. Only CVs 1, 3, 4 & 29 are supported. Therefore it appears CV2 cannot be adjusted. Hornby R8215 Decoder Manual
Bachmann 553 decoders can have CV2 adjusted. Bachmann decoder manual