Wavelengths of the visible spectrum
The comments on the question discuss this may not be about chemistry.
One could argue that colors are chemistry related because
they are associated with chemical substances: like minerals, chlorophyl, rust, dyes etc.
So colors seem to be properties of substances.
And that's fundamentally wrong.
Color is a function of the visual system of the viewer!
If that sounds surprising, think of color blind people, which see different colors.
Also, there are not just us - there are other animals, with different visual spectrum, partly including what we call UV.
Colors are not well defined
Actually, there are more than enough ways, even standards, to define which part of the rainbow is green, exactly - people working with visual media like print design can tell details.
And there are way more details than anyone could expect.
So, without a common definition of the colors, it's not the wavelengths that vary in different sources - it's the colors themselves.

To illustrate that color is more complex when looking closely, below you see a diagram defining color names. It is part of a formal standard which is in heavy use:

From https://en.wikipedia.org/wiki/CIE_1931_color_space