Touch Bar turning blue, Sidecar showing a blank one, or just missing the feature entirely: what to do for each

"Touch Bar" complaints on Mac forums fall into three completely unrelated buckets that happen to share a name: a physical Touch Bar strip visibly failing, Sidecar's software-simulated Touch Bar on an iPad behaving oddly, and people who simply miss the feature on newer Macs that never had one. Mixing these up wastes time, since the fix for one does nothing for the others.

Three different complaints, three different causes

Problem 1: a physical Touch Bar turning blue or discolored

If the Touch Bar on your actual MacBook (not an iPad in Sidecar) is developing a blue, black, or discolored patch, spreading over time, with or without flickering, this is consistently reported as a hardware display failure, not a software bug. It affects both the intel-era Touch Bar MacBook Pros originally. The common thread across reported cases: the Touch Bar itself is a small, separate OLED display and ribbon cable assembly, and that hardware degrades independently of the main screen.

Before assuming it's unfixable, rule out software causes with these steps, in order:

1. Restart into Safe Mode (hold Shift while starting up, or use the Options menu on Apple Silicon) and check whether the discoloration persists. If it's gone in Safe Mode, something software-level, not hardware, is involved, and a clean restart or update may resolve it.
2. Reset NVRAM (Intel Macs: hold Option-Command-P-R during startup for about 20 seconds) and reset the SMC (instructions vary by model; check Apple's current support page for your exact MacBook). The SMC controls several hardware functions on Intel Macs including, on T2-equipped models, aspects of the Touch Bar.
3. Take a screenshot while the discoloration is visible. If the screenshot shows a normal Touch Bar with no sign of the issue, that confirms it's a physical display artifact rather than something macOS is rendering incorrectly, since a true software glitch would usually also appear in a screen capture.

If none of that changes anything, you're very likely looking at a hardware fault in the Touch Bar's own display assembly. This typically requires a display or top-case replacement, since the Touch Bar is not a separately serviceable part on most Touch Bar MacBook Pro models. Check whether your specific symptom and model qualify for any active Apple repair program before paying for a replacement out of pocket, since Apple has run extended service programs for specific MacBook Pro display issues in the past.

Problem 2: Sidecar's virtual Touch Bar is blank or won't customize

Sidecar, Apple's feature for using an iPad as a second Mac display, includes a simulated Touch Bar that appears at the bottom of the iPad screen, even on Macs that have never had a physical one. This is a documented, intentional feature. What's also long-documented, across many macOS and iPadOS versions, is that it's finicky:

• A mostly blank bar showing only a thin line at one end, especially when trying to customize the Control Strip from System Settings, is a widely reported Sidecar quirk rather than something specific to your setup.
• Dragging icons to customize the Sidecar Touch Bar frequently doesn't work the way it does for a real one, particularly on Macs with no physical Touch Bar of their own.

Things worth trying, roughly in order of how often they've helped people:

1. Disconnect and reconnect the Sidecar session entirely, rather than trying to fix it live.
2. Toggle Show Touch Bar off and back on in Sidecar's own preferences (System Settings > Displays > your iPad's name).
3. Restart both the Mac and the iPad, not just one.
4. If you're on a Mac with no physical Touch Bar, try opening and closing the lid, or connecting and disconnecting an external display; several reports describe the Sidecar Touch Bar starting to work only after a display configuration change like this.
5. Check your Mac's Firewall settings (System Settings > Network > Firewall): "Block all incoming connections," if enabled, has been reported to interfere with Sidecar's Touch Bar and Apple Pencil features specifically.

If none of this resolves it, treat the Sidecar Touch Bar as a nice-to-have rather than something to depend on. The Control Strip and app-specific controls it's meant to show are convenience features, not required for anything Sidecar otherwise does.

Problem 3: you miss having a Touch Bar at all

Apple stopped shipping new Touch Bar MacBook Pro models in 2021, replacing it with physical function keys across the current lineup. If your complaint is simply that newer Macs don't have the feature, that's a hardware and product-line decision Apple made years ago, not something a setting or update changes. The MacBook Neo, MacBook Air, and current MacBook Pro models all use standard function keys.

Getting Touch Bar-style functionality without the hardware

If what you actually miss is the quick-access controls the Touch Bar used to provide, several of its core jobs have equivalents elsewhere in current macOS:

• Control Strip functions (brightness, volume, media controls) are available through Control Center in the menu bar on every current Mac, and through the standard function key row.
• Typing suggestions, one of the Touch Bar's original functions, are available inline as you type in most apps without any special hardware.
• App-specific Touch Bar controls that some apps offered, like scrubbing a video timeline or picking a color, generally have standard on-screen equivalents in the app itself; nothing meaningful was lost there, just moved.
• A genuine second touch-input surface, if that's specifically what you want, is what Sidecar's virtual Touch Bar on an iPad is trying to replicate, with the caveats in Problem 2 above.

There is no supported way to add a physical Touch Bar to a Mac that didn't ship with one.

The short version

• A physical Touch Bar turning blue or flickering is almost always a hardware display failure; rule out software with Safe Mode and an SMC/NVRAM reset first, but expect a repair if those don't help.
• Sidecar's virtual Touch Bar on an iPad is a separate, long-documented feature with its own, separate quirks, especially on Macs with no physical Touch Bar of their own.
• Current Macs do not have a Touch Bar and Apple has not shipped one in years; this is a hardware decision, not a setting to restore.
• Most of what the Touch Bar did is available through Control Center, the function key row, and in-app controls on current Macs.