Not late. While the task isn't solved, it is possible to join. Any restrictions for participation.

Task was placed.

Second is nothing or is that the hint?

Spectral/spectrum color.

You must think.))) The task was checked.

It's your answer?

Well, white colour spectrum would fit the description more, as colours are one hint.
But both white light spectrum and white colour spectrum seem to be possible.
Yeah can't make anything else out of it beside either of them, want me to pick?

White light spectrum - not correct answer. You must think. I won't give you any more simple problems.) The community well solves, and I think simple problems are uninteresting.

My answer is: White light dispersed into visible spectrum.

infra red

Not correct answer.
Not correct answer.

You correctly think, but solved not completely.

Ultraviolet

Not correct answer.

rainbow

Not correct answer.