I love blue ,like the blue skie
I like blue as well. It is one of the three primary colors, along with green and red.
Blue signifies a lot of this,its an adjective that qualifies a noun
Blue lies between green and violet on the spectrum of visible light. It is also the color the sky appears.
The rainbow has many colors ,do you know how many?
Well rainbows have a gradient of colors. I don't know how many but there are quite a few.
Have you heard of blue ray ?
Sure, Blu-ray is a digital optical disc storage format. They replaced DVD's in the 2010's.