Char got the red mobile suit because, in The Origin , he was assigned a customized Zaku II painted in his personal red colors, and that color scheme became part of his “Red Comet” image. The red suit wasn’t a separate magical upgrade so much as a specially marked command machine that helped make him stand out as a top ace.

What happened

In the The Origin storyline, Char rises through Zeon’s ranks and is eventually given a mobile suit to pilot. His Zaku is modified as a commander’s unit, including the red paint and the horn-like head detail, which made it visually distinct from ordinary Zakus.

Why it matters

The red color is tied to Char’s legend: after his high-speed combat exploits, people come to know him as the Red Comet. So the suit’s color is both practical branding and part of his reputation.

In plain terms

  1. Zeon gave him a special Zaku II.
  2. It was painted red as his personal/command color.
  3. His combat performance made the red suit famous.

TL;DR: Char didn’t “find” a red mobile suit—he was given a customized red Zaku II, and that suit helped cement his Red Comet identity.