Pigmentation of aromates
It is indeed nitrobenzene.

You really should look at the compounds, literally, because chemistry is ultimately an experimental science.

That being so, you can still note that the conjugated nitro group with its electronegative atoms gives relatively low-lying vacant orbitals into which electrons can be excited.  These orbitals can be accessed by absorbing short wavelength (violet/blue) visible light leading to a yellow color.