Web design for color blind users - PowerPoint PPT Presentation

Web design for color blind users

Presented by

Rajalekshmy Usha

HCI assignment 4

12/11/2001

Afflicts 8 percent men and 0.5 percent women

Most services and companies use no or less consideration for this group. For example,

some instructions say “press the red button”

Color coded pills

Red warning and green safety light on some machines

• Red-Green Color Vision Deficiency:
• Most commonly referred to as “color vision deficiency” since the sufferers are not entirely blind to colors
• Total Color Blindness:
• Rare, but is present across all ethnic groups
• Two types:
• Typical : complete failure to discriminate colors
• Atypical : low color sensitivity, only clear colors detected

• Approximately 10 million people in United States are blind and visually impaired
• At least 1.5 million blind and visually impaired Americans use computers (source :American Foundation for Blind)
• Males are more prone to color blindness
• 7 percent males and 0.4 percent females suffer from red-green color blindness

• A normal person sees a 5 revealed among the dots
• A red-green color blind person sees a 2 revealed in the dot

• Most of the current web designers give little or no consideration for color blind users
• Not willing to sacrifice minor design elements for the majority of the users
• However popular web sites are simple and not overloaded with colors

• http://www.moviephone.com/
• Light orange background in the left navigation menu
• Different color links with green and orange which blends in
• http://www.wired.com/:
• garish colors
• too much even for normal users
• Red and green backgrounds are kept together

• http://www.amazon.com/
• Simple and elegant
• Used distinct colors for menus, images etc
• No red and green colors together
• http://www.hotmail.com/
• The butterfly icon may not be that distinct
• http://www.whitehouse.gov/:
• Again simple and plain
• but fonts on the menu tab could have been larger

• Make internet accessible to color blind users
• Provide an opportunity for web-designers, system developers and for all society

-Represent worse-case scenario since the fonts are small and the

backgrounds are highly saturated

-Brightness of the font increases from top to bottom and

the brightness of the background increases from left to right

- I will use this color swatch for web designing

Click on the red button

• Use ALT = ‘…’ text for all the images.
• Use JavaScript Mouse over events to describe the status event description of all the images
• Use blue, yellow, white and black to really distinguish items
• Provide numerous links with a text version , if you cannot do without graphics
• Provide labels next to any colored indicators
• Emphasize important with larger fonts, color highlight(proper ones!) and outlining boxes
• Provide visual cues like icons or arrows if there are no underlining for text links

Next

• Provide strong contrast between background and the foreground colors

Effective and non-effective hue contrast is shown in the picture alongside.

DON’T :

• Use red/purple/gray/brown/green next to or to the top of red/purple/gray/brown/green
• Use various shades of one color
• Use single light bulb that changes color from red to yellow or green to yellow under any circumstances
• Use colors in images to denote special areas, such as bar charts, maps, and navigation bars
• Overload the web site with large number of visually striking buttons, garish colors and extreme imageries.

AAAAA

AAAAA

( good format )

hotel

phone

water

(email icon - bad format! )

DON’T :

• Use decorative , complicated or cursive fonts
• Roman typefaces are effective
• Decorative typefaces are not effective
• Condensed typefaces are not as effective
• Sans serif type faces are effective
• Extensive use of italics – oblique or condensed
• Upper and lowercase of a typeface is more readable
• Italics and bold types are not as effective

• Give information feedback by giving instructions, which refers to objects e.g. “press the button marked “ON” or “wait for the light on the left”
• Strive for consistency throughout while designing the websites
• Do regular usability testing – it provides opportunity for revision and improvement
• Compactness and branching factors of web page

• Black and white works best
• Never solely rely on colors
• Enhance each use with an image, shape, positioning or text
• Use bright colors – they are easiest to tell apart
• Use the appropriate back ground so you can make even the less safe color visible
• E.g. red against white, green against black,turquoise against black, magenta against black.

• www.firelily.com/opinions/thumb.html
• http://www.firelily.com/opinions/color.html
• www.vischeck.com
• http://newmanservices.com/colorblind/default.asp
• http://members.aol.com/nocolorvsn/color5.htm
• http://www.visibone.com/colorblind/
• http://trace.wisc.edu/world/web/