Final answer:
The color vacuum tube that should be used for trace metal analysis is green.
Step-by-step explanation:
The color vacuum tube that should be used for trace metal analysis is green.
When analyzing trace metals, it is important to use a color that will not interfere with the colors being observed. Green is an ideal color because it does not absorb or reflect any specific colors, allowing for accurate analysis of the metal ions present in the sample.
By using a green vacuum tube, the trace metal analysis can be performed with precision and reliability.