Current behaviour of the reverse video bit in FCM makes no sense

[gardners]

Test Environment (required)
Any MEGA65 Core

Describe the bug
Setting the reverse video bit in FCM causes each 8-bit colour value to be inverted.
This just messes up colours, without making background pixels (normally value $00) show the foreground instead of the background colour, which is what feels more natural for FCM reverse display.

NCM has a similar issue.

To Reproduce
Display FCM glyph with reverse bit set in colour RAM byte 1.

Expected behavior
FCM/NCM glyph appears with correct colours, but transparent pixels are foreground colour, not background colour.

Screenshots

Additional context
Required for MEGAphone