The Norm: Millennials mostly view photography on bright screens in smart-phones, tablets, PCs, or even on TVs. These back-lit devices use Red, Green and Blue lights directed onto a dark/blackish background. Most all of the colors that humans can see are created from combinations of these RGB primary lights being transmitted directly to our eyes. When processing/preparing or viewing a photo file for every-day purposes, Android, Windows, and iMac software perform best when operating under its default standard RGB color environment (sRGB.) JPEG formatted photo files using this same sRGB 8-bit standard are the created by cameras, archived, and used in email and/or posting on web pages (internet.) The file contains all the photo’s colors pixel-by-pixel in a standardized “sRGB” digitization so that everybody’s display/monitor can produce the same visual color impact as what was taken by the camera, processed and observed by the originator.
Printing: Unfortunately, colors and “punch” are different when printing that JPEG. Photos that may have been awesome when viewed on your smart-phone sometimes look dull after you printed them. The reason: When looking at a sheet of white paper, our eyes receive a balanced combination of colored light being reflected off the paper’s surface. White parts of paper reflect most of the white-light provided by the Sun (or by the lights in the room.) If the surface is covered by colored Ink, that part reflects a different color combo. So sRGB values embedded in a photo file must be cross-referenced to something that is “similar” when reflected off a white paper. A locally attached ink-jet type printer product integrates conversion software that adapts the sRGB color info contained in the JPEG file into its own native ink formulas/pigmentation/dye to best match the photo-paper characteristics. Similarly, outside photo printer shops like Snapfish, Wallgreens, etc. also expect sRGB and JPEG files and tune their hard-copy printing Ink mix accordingly.
COMMERCIAL printing: When supplying press-ready photo or image files to commercial printing operations (for magazines, publishers, and/or printing by external photo/image connoisseurs,) different rules for processing and archiving apply, especially for color. All printers may not use the identical ink formulations and paper types. Further their sRGB conversion algorithms may differ. Hence a JPEG photo may print in a magazine color-wise different than the photographer viewed on a display. Some printers may require the originator to provide something other than an sRGB JPEG file, specifically a format employing 16-bit color rather using an industrial standard CMYK color gamut, typically TIFF type and extremely large.
CMYK stands for Cyan, Magenta, Yellow, and Key (black). CMYK, or 4-color processing, is the industrial standard for printing. The idea is that white is the natural state of a sheet of print paper. Cyan, magenta and yellow (inks) combine to cover up the white in varying degrees and combinations, producing every possible intermediate color imaginable.
Some photo professionals opt to use special CMYK display monitors and have cameras that can take photos using the CMYK color gamut rather than sRGB. CMYK 16-bit color photo files, when displayed on normal monitors and tablets produce colors that are quite subdued.