Why do larger gases such as neon produce more color bands (line spectra) than smaller gases like hydrogen?

The large gases produce so many spectral lines because of high numbers of energy levels.

Since, Hydrogen has only one shell so It will produce very less spectral line on excitation.

On the other hand large gases like neon has so many shells or energy levels. So when they are excited they produce so many  spectral lines.

Hence, we can conclude that the large gases produce so many spectral lines because of high numbers of energy levels.

To know more about spectral lines, refer to the link:

link

he would use the colour black