Warm monochrome, and the one accent rule

Colour is the loudest tool in the kit, which is exactly why it should be the last one you reach for. A near-black, a warm paper and a single sand tone can carry an entire brand if the type and space are doing their work.
Let the photography be the colour
When the palette is quiet, one warm still-life photograph becomes an event. The eye lands on it precisely because nothing else is competing. Monochrome is not the absence of colour. It is colour, saved for when it counts.