Color-Blind Safe IntelliJ Plugin - 4 IDE Themes with Measured Syntax Contrast (Red-Green & Blue-Yellow)

Four IDE themes for developers with colour vision deficiency, and for teams that have one on the team. Why this exists: most syntax themes separate keyword / string / number / function / type by HUE alone, and red-vs-green is the most common pair. For a protan or deutan eye those two collapse into the same yellow-brown, so errors, added lines and removed lines stop being different colours. What was actually done, and what you can re-check: - 4 themes x 15 palette keys = 60 hex values. - 52 WCAG 2.1 contrast checks (11 foreground keys per theme against their background, plus main text on the alternate surface and on the selection colour). Lowest single result: 4.99:1. Main editor text: 14.06:1 / 17.76:1 / 16.85:1 / 14.35:1. - 84 token-pair separations (keyword, string, number, function, type, main text, comment text - 21 pairs per theme) measured as CIE76 dE*ab AFTER running each colour through the Machado, Oliveira & Fernandes (2009) colour-vision-deficiency simulation for the deficiency that theme targets. Lowest single result: 16.1. Universal Dark AA holds a floor of 23.6. - The hue families follow the Okabe-Ito Color Universal Design recommendation (blue, amber-yellow, bluish-green, violet - never red-vs-green as the only distinction). The exact values were re-solved per background so the contrast floor and the simulated separation hold together; they are not the published swatches copied over. The four themes: 1. Universal Dark AA - Red-Green Safe. The everyday dark theme. Free on JetBrains Marketplace, complete, nothing held back. 2. Universal Dark AAA - Red-Green Safe High Contrast. Same hue logic, every token at 7:1 or better, for glare, bad monitors and low vision. 3. Universal Light AA - Red-Green Safe. Daylight, screen sharing and projectors. 4. Universal Dark AA - Blue-Yellow Safe. For tritan vision, where blue-vs-green and yellow-vs-violet are the pairs that collapse instead. VCS colours follow the same rule: 'added' is bluish-green and 'removed' is sand or rose depending on the theme, so the diff gutter stays readable when red and green do not separate. Not affiliated with, or endorsed by, JetBrains s.r.o. 'IntelliJ' is named here only to say which IDE these themes install into.

def greet(name):
    # say hello
    return f"hi {name}"

def greet(name):
    # say hello
    return f"hi {name}"

def greet(name):
    # say hello
    return f"hi {name}"

def greet(name):
    # say hello
    return f"hi {name}"