Understanding Contrast
Contrast Ratio ### 
WCAG Grade

1. Convert the HEX color to RGB.
RGB 1  RGB 2 
2. Divide each color by 255 to get a linear value between 0 and 1.
r: g: b: 
r: g: b: 
3. Apply Gamma Correction
If value < than .03928, divide by 12.92.
Otherwise, add .055 and divide total by 1.055 and take result to the power of 2.4
r: g: b: 
r: g: b: 
4. Calculate luminance
(r X .2126) + (g X .7152) + (b X 0.0722)
Luminance 1  Luminance 2 
5. Determine contrast between colors.
(L1 + 0.05) / (L2 + 0.05)
Contrast Result
Credits:
 NES.css
 Lee Verou's Contrast Ratio Site(helped me understand the math)
 The Princess Icon by Freepik from www.flaticon.com is licensed by CC 3.0 BY
Reference
 Understanding Gamma Correction
 Learn more about Gamma Correction
 Relative luminance
 Stacie's list of Accessibility Resources
 1. Wavelength of Maximum Human Visual Sensitivity Susan Zhao 2007
Parts of the article were initially posted as 'The Bright Stuff' at: staciearellano.com/thebrightstuff/in 2019.