South Asian Skincare Help

Hi! I'm a fairly light-skinned Indian living in the East Bay Area. When I wake up, I'm about a W2-W3 loreal truematch shade (light/light-medium). Throughout the day however, my skin darkens significantly (no matter what I do, even if I'm inside) and I become a W5-W6 medium brown shade.

To clarify, I have NOTHING against being darker/more brown skinned. What annoys me is literally having such drastic changes to my skin within one day to the point where I literally need different sets of foundation/concealer. Once I wash my face I become light/light-medium again though. HELP!!!