macOS Touch Bar Icons Location
If you're interested in customizing the touch bar icons Apple provides some templates to get started:
And while they're not specific to the touch bar – which has its own design guidelines – there's a bevy of additional design resources available on the HIG.
The Touch Bar system icons are all located in /System/Library/CoreServices/SystemAppearance.bundle/Contents/Resources/Assets.car.
To name a few examples, they are named like TouchBarControlStripSpotlight or TouchBarControlStripSiriContent.
If you want to inspect and also change them you can use the ThemeEngine app to open the .CAR files. You can find the app/project here: https://github.com/alexzielenski/ThemeEngine
Sadly the ThemeEngine.app fails to display all icons. Some appear to be empty, but I guess thats a problem with the app. Maybe there's another, more reliable way to open .CAR files.
Touch Bar is introducing these new icons:
Here are the references: (You can find them and all others images in NSImage.h)
NSImageNameTouchBarAddDetailTemplate, NSImageNameTouchBarAddTemplate, NSImageNameTouchBarAlarmTemplate, NSImageNameTouchBarAudioInputMuteTemplate, NSImageNameTouchBarAudioInputTemplate, NSImageNameTouchBarAudioOutputMuteTemplate, NSImageNameTouchBarAudioOutputVolumeHighTemplate, NSImageNameTouchBarAudioOutputVolumeLowTemplate, NSImageNameTouchBarAudioOutputVolumeMediumTemplate, NSImageNameTouchBarAudioOutputVolumeOffTemplate, NSImageNameTouchBarBookmarksTemplate, NSImageNameTouchBarColorPickerFill, NSImageNameTouchBarColorPickerFont, NSImageNameTouchBarColorPickerStroke, NSImageNameTouchBarCommunicationAudioTemplate, NSImageNameTouchBarCommunicationVideoTemplate, NSImageNameTouchBarComposeTemplate, NSImageNameTouchBarDeleteTemplate, NSImageNameTouchBarDownloadTemplate, NSImageNameTouchBarEnterFullScreenTemplate, NSImageNameTouchBarExitFullScreenTemplate, NSImageNameTouchBarFastForwardTemplate, NSImageNameTouchBarFolderCopyToTemplate, NSImageNameTouchBarFolderMoveToTemplate, NSImageNameTouchBarFolderTemplate, NSImageNameTouchBarGetInfoTemplate, NSImageNameTouchBarGoBackTemplate, NSImageNameTouchBarGoDownTemplate, NSImageNameTouchBarGoForwardTemplate, NSImageNameTouchBarGoUpTemplate, NSImageNameTouchBarHistoryTemplate, NSImageNameTouchBarIconViewTemplate, NSImageNameTouchBarListViewTemplate, NSImageNameTouchBarMailTemplate, NSImageNameTouchBarNewFolderTemplate, NSImageNameTouchBarNewMessageTemplate, NSImageNameTouchBarOpenInBrowserTemplate, NSImageNameTouchBarPauseTemplate, NSImageNameTouchBarPlayheadTemplate, NSImageNameTouchBarPlayPauseTemplate, NSImageNameTouchBarPlayTemplate, NSImageNameTouchBarQuickLookTemplate, NSImageNameTouchBarRecordStartTemplate, NSImageNameTouchBarRecordStopTemplate, NSImageNameTouchBarRefreshTemplate, NSImageNameTouchBarRewindTemplate, NSImageNameTouchBarRotateLeftTemplate, NSImageNameTouchBarRotateRightTemplate, NSImageNameTouchBarSearchTemplate, NSImageNameTouchBarShareTemplate, NSImageNameTouchBarSidebarTemplate, NSImageNameTouchBarSkipAhead15SecondsTemplate, NSImageNameTouchBarSkipAhead30SecondsTemplate, NSImageNameTouchBarSkipAheadTemplate, NSImageNameTouchBarSkipBack15SecondsTemplate, NSImageNameTouchBarSkipBack30SecondsTemplate, NSImageNameTouchBarSkipBackTemplate, NSImageNameTouchBarSkipToEndTemplate, NSImageNameTouchBarSkipToStartTemplate, NSImageNameTouchBarSlideshowTemplate, NSImageNameTouchBarTagIconTemplate, NSImageNameTouchBarTextBoldTemplate, NSImageNameTouchBarTextBoxTemplate, NSImageNameTouchBarTextCenterAlignTemplate, NSImageNameTouchBarTextItalicTemplate, NSImageNameTouchBarTextJustifiedAlignTemplate, NSImageNameTouchBarTextLeftAlignTemplate, NSImageNameTouchBarTextListTemplate, NSImageNameTouchBarTextRightAlignTemplate, NSImageNameTouchBarTextStrikethroughTemplate, NSImageNameTouchBarTextUnderlineTemplate, NSImageNameTouchBarUserAddTemplate, NSImageNameTouchBarUserGroupTemplate, NSImageNameTouchBarUserTemplate
Example use in Obj-C:
NSImage *image = [NSImage imageNamed:NSImageNameTouchBarUserTemplate];
Example use in Swift:
let image = NSImage(named: NSImageNameTouchBarUserTemplate)