Any painting experts here?

[AlaskaThunderfuckHiiiiiiiii]

Quick question
im in the middle of painting my hallway and DH has put some wood panels under the stairs as it was wood chipped and not in good state. I have painted this white but there is a wee rectangle at the bottom of the stairs that I don’t know what to do with

leave white like the rest of the under stairs or paint same colour as wall?

photos attached to try and explain what I mean!

Same colour as the wall.

Same colour as the wall, not white.

Another for the wall colour. It’s the same plane.

Thanks for everyone for the replies so far, I was going to paint it the same colour as the wall when I started then when I was painting the white on the underside I started to doubt the choice!