Windex damage on MacBook screen causing color glitches

FWIW, Windex is a very harsh ammonia based cleaner with soap and solvents that will destroy any screen coating and if it enters any display will destroy it.

Your only solution is to get the screen replaced.

Next time for any product with a display be sure to check the manufacturer recommended method for cleaning the display.

Here is: How to clean your Apple products - Apple Support

it appears liquid got into the Mac. Per Apple: “If liquid makes its way inside your Apple product, get help from an Apple Authorized Service Provider or Apple Store as soon as possible. Liquid damage isn't covered under the Apple product warranty or AppleCare Protection Plans, but you may have rights under consumer law. If you plan to visit an Apple Store, make a reservation at the Genius Bar (available only in some countries and regions).”

The issue mentioned by others regarding Windex are valid, but your specific issue would have occurred even if you had used water since your screen damage is from liquid getting inside the Display Assembly.

When cleaning any electronic device, you want to lightly moisten the microfiber cloth so the cloth is just barely damp. You also need to be very careful not to get a damp cloth near the edges or any openings just in case some excess liquid happens to leak from the cloth. If you wring the dampened cloth and liquid drips from it, then that cloth is too wet.

Never, ever spray liquid on any device....it will not end well. Always spray the cloth with only a minimal amount, or if using water....just use a small drop of water & let it absorb into the cloth a moment before wiping it on the device.

If a microfiber cloth lightly dampened with water is insufficient to remove some grime from the display, then try using an LCD screen cleaner.....again only lightly spray the microfiber cloth so it is just lightly dampened. Just be careful that the LCD screen cleaner is not using any strong chemicals (some may, but the better ones will not). There have also been times when there are little spots (dots) which won't wipe off where I need to gently/lightly use my fingernail to nudge & break up the spot of grime before being able to have the cloth remove it.

FYI, when I clean a laptop's display, I will open the lid 90º and place the back of the laptop's Display/Lid onto a flat smooth table (best to have a thin piece of cardboard or cloth on the table so not to scratch the metal or the tabletop) so that the base of the laptop (Keyboard/Palmrest) are in the air (hold onto the base to keep it from closing or tipping over). I find wiping the display this way is much easier since the display is solid allowing me to better rub it clean. It also allows me to be careful when I'm around the edges of the display. But be careful since you don't want to press too hard or you can crack the display.

Bummer. Hope you have AppleCare+.