Help me envision my new hallway?

[Slitherie]

Quite a wide hallway which narrows off at the end and turns into a narrow corridor. However the area near the front door is wide and bright. So at the minute it has white walls, cheap “pine effect” laminate, white stair banister and a cheap “pine effect” shoe cabinet from Argos.

I want to buy this (see pic) to replace the shoe cabinet so everything else needs to suit it.

Im thinking sage green walls but what flooring? Do I leave the stair banister white? What do I put on the massive two story bare wall going up the stairs?

I don't know if it's still available, but Deluxe used to have an app where you used your camera phone and it 'coloured' the walls in the colour you select. Gives you an idea of what the walls/area would look like.