Colours always fascinated me and as designer I couldn't find any excuse not to do a little bit of research into Japanese colour nomenclature. Colours are an essential part of the Japanese culture whether you look at traditional paintings reflecting colorful sceneries like flourishing sakuras and Japanese maples, participate in a matsuri, look at the many beautiful kimono or even read some of the famous seasonal haiku.
Japanese perception of colours, as is often the case between different cultures, is different from that of a foreigner. For example, green is considered a variation of blue and when there is a word designating a pure shade of green (midori, みどり, 綠), it is often (ex. traffic lights) used interchangeably with aoi (あおい, 青い), meaning blue. There is also little to no differentiation between violet and purple—two colors that are very close one to each other, yet clearly distinguished in English language—both generally called murasaki (むらさき, 紫)
In order to help you understand some of these differences and learn to express even the most colorful ideas, I created a cheat sheet which contains both basic and more specific colors as well as as some related vocabulary.
You are free to distribute the chart wherever you want as long as the file remains intact and the work is properly credited.