Which of the following pairs correctly matches tungsten type to its color?

• A. Pure tungsten blue; thoriated tungsten red; Zirconium tungsten green
• B. Pure tungsten red; thoriated tungsten green; Zirconium tungsten brown
• C. Pure tungsten yellow; thoriated tungsten green/red; Zirconium tungsten brown
• D. Pure tungsten green; thoriated tungsten yellow/red; Zirconium tungsten brown

Answer: (D)

In TIG welding, tungsten electrodes are color-coded by alloy type to help you pick the right electrode quickly. Pure tungsten has no alloying elements and is commonly green. Thoriated tungsten contains thorium and is typically red, though some brands use yellow or orange variants. Zirconiated tungsten contains zirconium and is usually brown.

The pairing that matches this scheme is pure tungsten shown as green and zirconium (zirconiated) shown as brown, with thoriated tungsten acknowledged to appear in yellow or red depending on the brand. So the option listing pure tungsten green, thoriated tungsten yellow/red, and zirconium tungsten brown aligns with these color conventions, making it the correct choice.