What gave magma and lava a bright yellow colour?

Question: What gave magma and lava a bright yellow colour?
- Keywords:
  colour,
  heat,
  volcano
Asked by Abbiemooster to Kate on 20 Nov 2014.
- Kate Dobson answered on 20 Nov 2014:
  
  Magma in beneath the surface so we can’t see it, but lava (which is the same stuff once it’s been errupted) glows because it is so hot it is incandescent.

Question: What gave magma and lava a bright yellow colour?