30 days accessibility testing challenge

 

Day15 # Find the problem that affects someone who is colorblind


What Is Color Blindness?

There are many types of color blindness but it comes down to not seeing color clearly, getting colors mixed up, or not being able to differentiate between certain colors.

Types of Colour Blindness

Trichomaty

Normal color vision uses all three types of light cones correctly and is known as trichromacy. People with normal color vision are known as trichromats.

Anomalous Trichomatic

Anomalous Trichromacy is the most common category of color blindness. It is an impairment of normal color vision, not a complete loss. This occurs when one of the cones is altered in its spectral sensitivity. It can be red/green or blue/yellow depending on which cone is altered. The ability of anomalous trichromats to distinguish between hues is better than dichromats but still not normal.

The different anomalous conditions are protanomaly, which is a reduced sensitivity to red light, deuteranomaly which is a reduced sensitivity to green light, and is the most common form of colour blindness, and tritanomaly which is a reduced sensitivity to blue light and is extremely rare.



These problems can also be exacerbated by the environments in which people use websites. This could include low-quality monitors, bad lighting, screen glare, tiny mobile screens, and sitting far away from a huge television screen.

Text Readability

To ensure text is readable it should pass accessibility guidelines based on the combination of text color, background color, and text size as follows:

“WCAG 2.0 level AA requires a contrast ratio of 4.5:1 for normal text and 3:1 for large text (14 point and bold or larger, or 18 point or larger).” — WebAim color contrast checker

This illustrates how contrast is based on the combination of color and size.

Color Combinations

In the physical world, you can’t always control which colors appear next to one another: a red apple may have dropped and nestled itself into some green grass. However, we can control the colors we use to design our website. The following color combinations should be avoided where possible:

  • green/red
  • green/brown
  • blue/purple
  • green/blue
  • light green/yellow
  • blue/grey
  • green/grey
  • green/black

Comments

Post a Comment

Popular posts from this blog

WCAG 2.0 - WEB CONTENT ACCESSIBILITY GUIDELINES

Image
Day 5# 30 days of Accessibility testing Day#5 Read the 12 guidelines of Web Content Accessibility Guidelines (WCAG 2.0.) Write a short post on one of them    The Web Content Accessibility Guidelines (known as WCAG 2.1) are an internationally recognized set of recommendations for improving web accessibility. They explain how to make digital services, websites, and apps accessible to everyone, including users with impairments to their: • vision - like severely sight impaired (blind), sight impaired (partially sighted) or color blind people • hearing - like people who are deaf or hard of hearing • mobility - like those who find it difficult to use a mouse or keyboard • thinking and understanding - like people with dyslexia, autism, or learning difficulties WCAG 2.0 is based on 4 design principles: • Perceivable - Information and user interface components must be presentable to users in ways they can perceive. • This means that users must be able to perceive the inform...
Read more

Accessibility testing challenges

Image
Day 24 # L earn about accessibility law in your country UK Most public sector websites and mobile apps do not currently meet accessibility requirements. For example, a recent study found that  4 in 10 local council homepages failed basic tests for accessibility . Common problems include websites that are not easy to use on a mobile or cannot be navigated using a keyboard, inaccessible PDF forms that cannot be read out on screen readers, and poor color contrast that makes the text difficult to read - especially for visually impaired people. You may be breaking the law if your public sector website or mobile app does not meet accessibility requirements. The accessibility regulations came into force for public sector bodies on 23 September 2018. They say you must make your website or mobile app more accessible by making it ‘perceivable, operable, understandable and robust’. You need to include and update an accessibility statement on your website. The full name of the accessibility re...
Read more

Day 6 – Assistive Technology

Image
        Day 6# Learn about assistive technologies and share one you loved (hardware)     • Assistive technology is any device, software, or equipment that helps people work around their challenges. • Some examples of assistive technology are text-to-speech and word prediction. • Assistive technology includes low-tech tools, too, like pencil grips. Sip-and-Puff Systems Sip-and-puff systems are used by students who have mobility challenges, such as paralysis and fine motor skill disabilities. These systems allow for control of a computer, mobile device, or some other technological application by the child moving the device with his or her mouth. Similar to a joystick, the child can move the controller in any direction and click on various navigational tools using either a sip or a puff. An on-screen keyboard allows the child to type using the same movements. Sip-and-puff systems are a type of switch device, which refers to the technology used to replace...
Read more