I love all the patterns and color in your room!

Address your lighting. Increase wattage if able, add more lights and layer lighting.

Replace the dark scroll wall hanging with lighter colored art work. Reducing visual weight as well as being actually lighter in color.

Since you have shutters or blinds you could remove the curtains entirely.

If you want to have the curtains.... personally I like your current curtains, if you hang them higher and wider it will look lighter.

It looks like you have high ceilings, lucky you! By raising the curtain height you will visually expand the room making it seem lighter. By hanging the curtains wider off the sides of the window with just a bit covering molding you will visually expand the window size making the window seem larger, this will also brighten the room.

If you do all of the above and it is not light enough then time to pick up a paint brush and go to town!

IMHO all the windows should match, do the sheer on the French door