Polka-Dot Paint

Sometimes, cartoon characters will paint with one or two strokes in colour combinations that simply cannot be done that way in the real world, such as stripes, checks, polka dots, or even more elaborate patterns.

Finding one of these might be assigned to a naive person as a Snipe Hunt.

Examples of Polka-Dot Paint include:

Comic Books

In the French comic Les 4 As (The 4 Aces) about four kids (a sporty boy, a smart nerdy boy, a fat Big Eater and Supreme Chef, and a ditzy girl), the girl actually manages to paint a car with checkered paint, which she claims to have invented herself. The Smart Guy is stumped, of course. Strangely, the comic is without Magic and Powers and such.

Literature

One Norman Hunter book had the protagonists needing to fulfil a promise by painting with striped paint. They faked the effect by painting the stripes in advance and whitewashing over them. The 'striped paint' they then demonstrated was water, which removed the whitewash and left the stripes.

Live Action TV

In one episode of Home Improvement, Tim claims to have a machine that can scan anything and make a color of it. Perfectly reasonable at first, but then Tim scans Al, produces "A nice can of Al", and proceeds to paint his portrait on a wall with a paint roller. Everyone else is shocked or amused by this, so in-universe it's probably just a magic trick.

Video Games

Some of the Rainbow Pool paintbrushes from Neopets.
- And the Chia pops, the transmogrification potions, and the Lab Ray colors.

Western Animation

In the Modern Madcaps cartoon "Travelaffs", a passenger has his bag checked: A few strokes with a broad brush, and it's painted with a checkerboard pattern.
In "The Vanishing Private", Donald Duck paints a field cannon with red, green and yellow stripes, and black polka dots. All at once, with a single brush and bucket.
In "Easter Yeggs", Bugs Bunny paints Elmer's head blue with yellow polka dots in two strokes.
Wile E. Coyote has created painted tunnels by this means.
Tiny Toon Adventures would continue the Looney Tunes tradition from time to time.
An Indian camouflaging his horse in the Lucky Luke film Daisy Town swipes his brush back and forth on the horse, and behold! the horse is coated in an elaborate landscape.
Whenever something is drawn in Dog City, it's done this way.
In one of the episodes of Rockin' Kats, a paint was used which made white-red striped paint for every odd swipe and blue-yellow polka dot paint for every even swipe.
In the Pac-Man episode "Invasion of the Pac-Pups", Pac-Man and his neighbor Morris are painting a garage:

Pac-Man: What color is this, anyway?
Morris: Pink polka-dot.

To get jobs in the fire department, Ren and Stimpy use 'dalmatian paint' - one quick swipe each with a brush and they're white with black spots - Stimpy's tongue included.
In one episode of My Little Pony Friendship Is Magic, it's shown that rainbows are this. Pinkie Pie dips a hoof in the liquid rainbow and it retains seven distinct stripes of color, despite dripping off her hoof. She then licks it...and starts breathing multicolored fire!

Real Life

One type of Snipe Hunt is to send someone out looking for striped or tartan paint.
Many paint programs have a tool, typically represented by a paint bucket icon, that can fill an area with either a solid color or a pattern.