Hi good morning again,
I checked the colours available for the standard RadioMaster TX16S units, they are as follows:
The normal TX16S has black S1 and S2 knobs:
https://www.unmannedtechshop.co.uk/product/radiomaster-tx16s-mkii/
The TX16S MAX, has either black or red S1 or S2 knobs depending on which colour variant you select:
https://www.unmannedtechshop.co.uk/product/radiomaster-tx16s-mkii-max/
Hope that helps.
Regards,
David
Unmanned Tech Support