Challenge 2: Identify the Affected User Group — Possible Solution ==================================================================== THE SCENARIO ------------- A site relies entirely on color (red vs green) to indicate form field errors, with no icon or text label. WHO THIS MOST DIRECTLY EXCLUDES ------------------------------------ People with color blindness (a visual disability) — specifically, this is a textbook example of the exact problem the chapter's "who these techniques actually serve" section connects to visual disabilities. Red/green color blindness (deuteranopia/protanopia) is the most common form of color blindness, affecting a meaningful percentage of the population (disproportionately more common in men), and a red-vs-green distinction is precisely the pairing this specific, common condition makes hardest or impossible to distinguish. WHY ---- Someone with red-green color blindness looking at this form may see both the "error" state and the "valid" state as visually similar or even indistinguishable shades — with no icon, text label, or other non-color signal present, there is NO alternative way for them to tell which fields have errors. This directly violates the Perceivable principle from this chapter's POUR breakdown: the error information is only being conveyed through a channel (color) that a meaningful group of real users genuinely cannot perceive reliably. Note that low-vision or blind users are affected too, but for a slightly different reason: a blind user relying on a screen reader wouldn't perceive color information AT ALL regardless of which colors were chosen, since color is a purely visual signal a screen reader doesn't announce by default — this makes the problem even broader than just color-blind users specifically, though color blindness is the group MOST DIRECTLY and specifically implicated by the red/green choice described in this scenario. THE FIX (implied by the problem, previewing later chapters) ----------------------------------------------------------------- Pairing the color with a non-color signal — an icon (a checkmark vs an exclamation mark), explicit text ("Invalid email format"), or both — would let the same information reach users regardless of whether they can distinguish red from green, addressing the Perceivable principle by adding a second, color-independent channel for the same information.