Which mainstream title first shipped with a built-in colorblind mode toggle? I remember Battlefield 3 (2011) offering Deuteranopia/Protanopia options for the HUD palette, but I’m double-checking for an accessibility UI timeline I’m compiling as a UI/UX designer…
Pretty sure it’s Call of Duty: Modern Warfare 2 (2009) — it shipped with a “Color Blind Assist” toggle for HUD/nametag colors, beating BF3 by a quickscope or two (source: https://www.destructoid.com/modern-warfare-2-supports-color-blind-players/). If you’re counting patches, WoW added one in 2007, but not at launch — are you limiting to launch-day features only?