Enter test screens, the digital color swatches that you can use to dial in your color settings (such as the hue, saturation, contrast, and temperature).

We love that it shows the SMPTE color bars, aka the standard American TV test pattern as it switches between weather and news.

What looks like random blocks of color to the untrained eye is actually a carefully laid-out test pattern. For example, the colors yellow, cyan, green, magenta, red, blue actually goes from ...

The test patterns can be downloaded from the AVFoundation page on Apple's website under Related Resources > Color Test Patterns, with complete instructions available in Apple's support document.