Some things we are forced to believe, for example, when we look at this spruce, we are told that it is a blue spruce.
Yes, it's a stretch to call this color a shade of blue, just like indigo, which can be a shade of blue or green.
It’s easier not to play with words, but to say it the way it really is, this spruce is idigo.
Here you can see several shades of indigo, both with a green bias and with a blue bias.
We can say that the whole spectrum of indigo is present here, if we do not talk about ultra color.
Photos taken with a Sony Cyber-shot DSC-HX300 camera.
Author 
Ukraine.