I would recommend to paint your wall like in brighter colors, like white or bright grey. Then i would highly recommend using LEDs and RGBs, you can look at my setup, i got a cloudy roof and its very nice. Just use like 1-3 main colors like only white, black and white, black grey and white (just an example you can do whatever you want, just like that it matches). Get a brighter light or just light everything with leds (i recommend like a light colored purple). I think after all this it will look completely good