Find a wallpaper first and pick colors from the paper. When looking for paintchips to match the wallpaper, think about this: Better pick two or three shades away from the color of the wallpaper than one shade off (will look weird). If you'll get new curtains and bedding too, try to pick colors that are 'related' or repeated somewhere in your room. Limit yourself to three colors and one natural, for example yellow grey white and birch, see if you can find everything in those colors. Afterwards, once you start adding decorative things, add some more color if you like. Accents in orange or teal look great with grey and yellow! Good luck!
https://www.houzz.com/magazine/favorite-color-combinations-gray-and-yellow-stsetivw-vs~622534





https://www.houzz.com/photos/3555-residence-bedrooms-modern-bedroom-kansas-city-phvw-vp~644533

Thank you very much! You wew very helpfull! Let me know if you find some other thing!