Because those are the colors that the eye can see.
The colour that seven is equal to in Rainbow is violet.
green i think
Mystic topaz usually appears to display rainbow colours, with greens, blues and ... every single colour can be seen in one kaleidoscopic and magical stone.
Could be seven colors of the rainbow.... 7CR? 7 Cross Roads? 7 Cute Rabbits? Good question... No, it's definitely 7 colors of the rainbow.
Those are the colors of the spectrum of sunlight. Red, orange, yellow, green, blue, indigo, violet.
The sixth color in a rainbow is indigo. A traditional rainbow is made up of seven colors, which are red, orange, yellow, green, blue, indigo, and violet. Indigo is positioned between blue and violet in the spectrum.
a rainbow
Purple
Yellow
indigo
Yellow
the colour is rainbow.