Painting a lounge light and dark shades

Planning to paint the lounge two shades of the same colour, but I can remember if it should be the lighter shade opposite the windows (or patio doors) or adjacent. Room is south facing.
Anyone know ?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.