CSS media query for color-index

In the following value below does it mean tha开发者_StackOverflow社区t the ouput device must have 256 colors exactly or can the ouput device have 256 or less or must the ouput device have 256 or more? Can someone explain this to me in simple terms?

(color-index: 256)

From the W3C docs:

The ‘color-index’ media feature describes the number of entries in the color lookup table of the output device. If the device does not use a color lookup table, the value is zero.

From that description, and from the examples after it, it appears that the answer is that it is the exact number of colors in the index (should it exist).

You may specify a minimum with min-color-index.

(color-index: 256) matches any device with 256 colors exactly.

(min-color-index: 256) matches any device with at least 256 colors

it's the bit quantity for the applying object color

From my understanding it is exact and you can you min and max prefixes to determine ranges.

W3C Docs