Referring to colors with a high contrast ratio, usually one that meets or exceeds webAIM guidelines.

 

Math Accessibility Guidelines

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Typed text is more legible for those with cognitive or visual difficulties including dyslexia, dysgraphia, low vision, color blindness, and more. Variations in handwriting style, skewed text, writing that is too small or too big, block vs. cursive writing, and more can make handwritten text and math difficult to decipher. As such, it is highly recommended to work with typed text and equations over handwritten math.