Horrible, isn't it?
It can mean the colour of indigo (that is, blue, as in jeans) or it can mean a dye with a similar chemical structure.
This means that indigoid can, as well as blue, mean deep red, purple, or it can be something also called indigo carmine, which is obviously (indigo meaning blue and carmine bright red), yes, a sort of...
Unless you put it in acid, where it turns bright yellow.
The very worst thing about the word indigoid, though, is that it sounds like a description of a disease.
And just which part of the anatomy turns blue doesn't bear thinking about.
photo by Brian Lin
Word Not To Use Today: indigoid. This word comes from the Greek word Indikos, which means of India.