If you have some form of color vision deficiency and you've booted up The Outer Worlds, perhaps your first instinct was to check its accessibility options. You'll find no colorblind mode or related option in Obsidian's RPG, but that's intentional—according to studio design director Josh Sawyer. The Outer Worlds was designed from the ground up to accommodate players any mild-to-severe color vision deficiencies.
On Twitter, Sawyer addressed the lack of a colorblind mode by confirming that The Outer Worlds "was designed to be playable without color information." Sawyer references The Outer Worlds' co-director Tim Cain, who has a form of color vision deficiency verging on monochromatism.
Both Accessible.Games and the Game Accessibility Guidelines include advice and examples of best-practice implementation for colorblind accessibility features, which often take the form of on-off toggles. As the latter resource notes, color vision deficiencies manifest "in varying degrees of severity but if you design for the full 100% severity you'll also have covered the varying other degrees."
Cain himself also told Polygon that The Outer Worlds' UI designers had to create the game's interface entirely in grayscale before they were allowed to do a color pass. That said, this detail came up in an article about The Outer Worlds' small text size—another crucial accessibility concern and one that The Outer Worlds currently doesn't have options for.
In 2011, shortly after Cain joined Obsidian, he spoke with Gamasutra about how his gradual loss of color vision started to inform his approach to game design:
In my family, people lose their color vision over time. I started losing mine when I was twenty years old, and now I can see less than half the spectrum of colors. I am surprised at how many games give information solely with color variation, and I cannot play those games. It's not difficult to include a number or symbol or word in addition to a color change, but some games don't do that, in the name of minimizing UI.
Though some players may find that some more accessibility options would be welcome in The Outer Worlds, it's always noteworthy when developers talk about designing with accessibility as a top priority. Those lengthy design resources exist because games so often conflate accessibility with difficulty, or don't consider it at all.