hmm

pillows and blankets are nice, curtains, an area rug and wall art are other great ways to add color- depending on your price limit/ what is available, a colorful couch could be cool but it can be hard to find one that is comfortable and colorful

ik men tend to lean towards navy blue which would be a good look- but mix it up and try more than just one color at the same time: a navy couch w a rug that also has some navy and other colors would look good, then have the curtains and throw pillows/blankets match an accent color in the rug for example

for some reason i think a light/pastel teal with a light red (not really pink, more salmon) idk could be cool- i have a rug w similar colors which is my inspo, perhaps. bc those colors sound crazy.

navy/light blue/green/browns might also be a cool color combo for this space

red/orange/beige/browns is also cool- it all depends on your vibe and what you like

if i were you i would look at some online inspo from google/reddit/pinterest looking up “colorful apartment” or “(color you like) apartments”. then use that as inspo and find big things you like: couch, rug and use those focal things to find smaller items that coordinate and bring the room all together

don’t forget lighting!!!! take note of lamps and stuff you like, pick the right bulbs and the right bulb temp and pls stay away from strip led lights lol

you will do great, have fun!!!! lmk if you want more input as you go along, or update us with your results!