From where you are now, you could put a wash of the ground colour on the walls and the sky on the roof, each on it’s own layer above what you have now.
Set the blend mode for these layers to either Soft Light or Overlay and maybe adjust their opacity down to taste.
The orange on the walls will all be bounced light coming up from the ground and will tend to be more noticeable near the bottom of the walls and fading to next to nothing or indeed nothing, higher up away from the ground.
The roof on the other hand would be more or less picking up the sky’s colour more or less evenly.
Here is a very quick and rough example:
The internet is awash with information, often referred to as Colour Theory, on how colour and light interact with objects and how to render that in paint. And it is just as relevant to digital painting as traditional painting.
While digital can replace our tools and canvases, the need for the same traditional knowledge of; form, lighting, value and colour are the same as they ever were and should be studied still.