Office test files

[CeeBee]

You are correct. However monitors don't always reproduce accurate colors and neither do printers - but they can be calibrated (monitors definitely).
Long ago I had a color swatch that came with a video card, used for proper color calibration.
It is worthy to mention that the look of an object will be different depending on the light source used. Direct sunlight and incandescent bulbs will make it look in a way, fluorescent tubes typical for an office will make it look different (usually crappy).
See https://en.wikipedia.org/wiki/Color_rendering_index
Also different individuals have different perceptions of the very same colors and some have a 4th cone that enables them to see "extra colors".