What you're seeing when you put it through a prism is that you heat hydrogen up and it doesn't just glow like a white light, it just emits light at particular colors, a red one, a light blue one, some dark blue ones.
Tas, ko jūs redzat, kad to izlaižat caur prizmu, ir, kad jūs uzsildāt ūdeņradi un tas neizstaro tikai balto gaismu, tas izstaro gaismu noteiktās krāsās — sarkanā, gaiši zilā, dažos tumši zilos toņos.