Very useful CCT/tint shots!

Yup, most of my applications are just printing receipts, invoices, and some wiring diagrams.
Do you know any good quality color wheel manufacturer at reasonable price?

- Clemence

If his printer has a 6-colour ink system, it might print out colours better than the standard CMYK (3-colour + black) system. Otherwise, itā€™s probably missing out on the saturated hues, especially red, green, and blue. That could lead to more difficulty in distinguishing colours than would be the case with a proper colour wheel.