List of colors - Wikipedia
One problem I've constantly run into is having an online convention for naming flower colors. Wikipecia has a nice list that might prove useful, especially for posts like dirtrx z7nc, who is looking for a hot pink salvia.
Wikipedia has such a page, dedicated more to the names of colors used on web pages.
I prefer the RHS flower color wheel, and there is also the Pantene color-matching wheel. Both are actually a set of high-quality strips of glossy chips held together by a sturdy pin. The RHS set of four wheels has a hole punched in the middle that you can bring up to the flower for optimal matching. It is important while using these tools to be aware of ambient light conditions,especially to standardize them.
For computers, this means setting the monitors black-body temperature (measured in degrees Kelvin)and color balance with the buttons on the monitor, as well as using the same light in the room by the monitor. The RHS color wheel needs to be used outside.
The Wikipedia article has other uses, disclaimers, and limitations mentioned in their article.