Wednesday, February 5, 2014

Tools Part 1 - Contrast Analyzers

Colour Contrast Analyser

The Paciello Group

Today I was given a short list of tools to suggest to the IBM Designers for accessibility compliance. The first is a color analyzer by the Paciello Group. The analyzer is a simple .exe (for win) that compares two colors giving a AA or AAA pass/fail rating of  one color on top of another. The tool also gives contrast ratios for three types of color blindness: Protonopia, Deuteranopia, and Tritanopia.

Protonopia - (1% of males): Lacking the long-wavelength sensitive retinal cones, those with this condition are unable to distinguish between colors in the greenyellowred section of the spectrum.Dueteranopia - (1% of males): Lacking the medium-wavelength cones, those affected are again unable to distinguish between colors in the green–yellow–red section of the spectrum.Tritanopia- (less than 1% of males and females): Lacking the short-wavelength cones, those affected see short-wavelength colors (blueindigo and a spectral violet) greenish and drastically dimmed, some of these colors even as black. Yellow is indistinguishable from pink, and purple colors are perceived as various shades of red

Source: wikipedia

The tool is a free download, but the testing involves manual input of the hex colors which can take some time.

Contrast A (Best Reviewed)

Das Plankton

Cropped image of the Contrast A application.

Contrast A is a web tool and does not require a download. From their application:

Contrast-A checks color combinations for sufficient contrast and displays the results according to WCAG 2.0 (Luminance Ratio) as well as the results according to older accessibility guidelines, WCAG 1.0 (Difference in Brightness and Color).

Contrast A also emulates the view of tritanopia, protanopia, deuteranopia and full color blindness.

Colors on the Web

Colors on the web color analyzer is a very simplistic analyzer that you plug the hex codes in to for ration results. Contrast ration is given and a nice big red X until you pass the ratio. It gives priority 2 (AA) and priority 3 (AAA) results.

Juicy Studio Contrast Analyzer

Juicy studio also has created a simple website for entering hex codes. The results include ratios and a visual example.

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