There will be the one black door, so suggest you paint the rest of the wall and jibs one color of your choice. This photo is only for inspiration...I think the walls are too dark and muddy, especially for the basement room. Something like this? Colorful with a touch of black accent to connect with the black door.

This warm taupe would look good with that black door.

I gravitate toward texture, mixed materials, leather, organic elements, and a mix of vintage + modern

Why does this have to be a feature wall? Find some great art--doorways, stairs, graphic art for that side of the room and get mixed materials for rugs, furnishings.

Georgia O'Keefe's famous doorway

OnrO

Or get interesting rug for the floor to pull the eye in a different direction These are from West Elm

You have a fabulous space to work with. It could be a real statement, and can be painted any color you want.

wall moulding. it's not that expensive, an easy DIY, if you have a mitre box and mitre saw, and could limit your decor needs.

OP is looking for smart ways to further conceal the hidden doors

I would not want to make that wall a feature wall. I would keep it all one colour and be done with it. Can you show others parts of the space?

For the sports theme, (what sports in particular?):

This idea when photos are framed in black, black door and light gray walls. Furniture matches tone of floor. Game table

coffee table looks like fun.

You are not crazy about it - but wood slats might be your best bet.

Paint the whole wall including the doors in the same color then hang some art to take your eye to that.

Your idea of using wallpaper will work - there are many photos of people disguising jib doors with wallpaper:

Adding some type of trim/moulding/wood slats is a great way to truly disguise the doors:

Here is a before photo of a wall -

They wanted to disguise the door to the playroom off of the bonus room. Using a simple paneling wouldn't be trendy:

I didn't want to show similar looks to the the picture moulding shown by Lyn Nielson above - but there are many different ways to use traditional looking moulding to disguise the doors.

This one below looks more like something you'd use in a finished basement (and it's a simple way to do create a feature wall + disguise the doors):

This one below is too much for your basement - however, I just thought it looked cool!

Basically, you can do any type of trim that you want in order to disguise your jib doors.

Wood slats would work well - you could also use plain boards and make a painted slat wall vs. one made out of stained wood slats. It would be quite a bit less money.

Maybe something with glass. A wall of glass in the gym with a glass door might work.

I would use molding to create an interesting wall. I like the design in the photo because the molding is spaced evening and you don't have to worry about where the door is. Though I would have added base molding to the bottom of door so that it is less obvious, as long as it wouldn't rub the wall.

I’d look at mural wallpapers…it would be so cool!

Thank you all for taking the time to help! I’ve been contemplating doing the box molding on the wall, but I’m concerned that it might highlight every seam and door line on a 30-foot wall with jib doors. Additionally, the fourth doorway (the black doorway in the picture) will have a black glass pane barn door, and I’m unsure how that will look over the top.

I’ve also considered a mural wall, but a 30-foot wall with hidden doors and a barn door might create visual chaos. Plus, finding a mural that will work is not easy. I’ve also thought about ombré limewash, but I’m not sure if it lacks texture. When you look at the wall at night or from a distance, does it appear flat? That’s why I was thinking about big crocodile wallpaper with a more matte finish. My brain hurts just thinking about all these options! I’ll post my final decision if I get to the finish line.

Thank you all ! I have thought about doing