Calendar Icon

Macintosh HD –> Applications –> Calendar –> Show Package Contents –> Contents –> Resources –> Calendar.docktileplugin –> Contents –> Resources

Replace or edit App-empty.icns and keep the same file name.

I edited mine in Apple Preview to pitch black.

Dictionary Window CSS

Macintosh HD –> Applications –> Dictionary –> Contents –> Resources

Edit DefaultStyle.css, MainPageStyle.css & WikipediaStylesheet.css

Firefox

Pinch To Zoom

Open a new tab.
Type in about:config and press Enter.
In the search pane, type pinch and press Enter.
Enter these values for the pinch.in and pinch.out preferences:
browser.gesture.pinch.in – cmd_fullZoomReduce
browser.gesture.pinch.in.shift – cmd_fullZoomReset
browser.gesture.pinch.out – cmd_fullZoomEnlarge
browser.gesture.pinch.out.shift – cmd_fullZoomReset

Icons

In order for this to work on all icons you need to disable System Integrity Protection (Rootless)
Most system icons are located in

Macintosh HD –> System –> Library –> CoreServices –> CoreTypes.bundle –> Contents –> Resources

LiteIcon is the easiest way to change the majority of common finder and app icons.
Get LiteIcon

Downgrade To iTunes 12.6.2.20

sudo rm -rf /applications/itunes.app

iTunes High Contrast Mode

defaults write com.apple.iTunes high-contrast-mode-enable -bool yes

defaults write com.apple.iTunes high-contrast-mode-enable -bool no

Quickly Add Song Lyrics In iTunes

Get Lyrical

Messages Window CSS

Macintosh HD –> System –> Library –> PrivateFrameworks –> SocialUI.framework –> Versions –> A –> Resources

Open “balloons-modern.css” with TextEdit and change the background color.

body {
background-color: black;
margin: 0px 0px 0px 0px;
–dim-animation-time: 0.15s;
}

Mail – Read Receipts
defaults read com.apple.mail UserHeaders

If that command returns an error that reads, “The domain/default pair of (com.apple.mail, UserHeaders) does not exist,” type the following, replacing Name and [email protected] with your own:

defaults write com.apple.mail UserHeaders ‘{“Disposition-Notification-To” = “Name <[email protected]>”; }’

For example, the complete line could read something like defaults write com.apple.mail UserHeaders ‘{“Disposition-Notification-To” = “Heinz Tschabitscher <[email protected]>”; }’.

If the second command above worked, repeat the first one.

Word and Character Count – Contextual Menu
1. Automator – New Service
2. Run Applescript
3. Copy & Paste In Form
4. Save Service as “Word and Character Count”

on run {input, parameters}
tell application “System Events”
set _appname to name of first process whose frontmost is true
end tell
set word_count to count words of (input as string)
set character_count to count characters of (input as string)
tell application _appname
display alert “” & word_count & ” words, ” & character_count & ” characters”
end tell
return input
end run