[seewhatIsee]

The Himba tribe in Africa have an interesting perception of color which is believed to stem from their language[1]. For example, their language uses the same word for what westerners separately call green and blue. As a result, they cannot seem to distinguish the colors when presented to them.

[1] https://vimeo.com/120808489

[jessaustin]

"Grue" is actually pretty common: https://en.wikipedia.org/wiki/Blue%E2%80%93green_distinction...

[IIIIIIIIIIII]

And Russians see two different colors where Westerners only see "Blue".

http://www.pnas.org/content/104/19/7780.full

There are more examples.

[skyisblue]

The ancient Japanese also had one word for shades of green and blue.