noob baffled - lighter areas rendered as darker than those in shadow

[oompa_l]

hi

I am just trying to figure out why those surface in my model which are exposed to the sun are coming out darker than those with covering? is it bc in those that are covered light is bouncing off those surfaces more? is there a way to ensure that those 'uncovered' surfaces are the lightest? what am I missing..?

thanks!