To accommodate users who don’t see color differences, you can use other methods to accentuate data, such as high-contrast shading, shape, or texture. 
Applying text labels to data also helps clarify its meaning, while eliminating the need for a legend. 
The right contrast is vital to catching users’ attention in the first place. The vibrancy you choose for your design is likewise crucial to provoking desired emotional responses from users. How they react to color choices depends on factors such as gender, experience, age and culture. In all cases, you should design for accessibility – e.g., regarding red-green color blindness.

Color Theory for Accessibility

When using color, it is important that there is a sufficient color contrast between different elements of your design. Higher contrast makes it easier to see, whereas lower contrasts may make it difficult for users to see in high or low light environments.
W3C recommends the following contrast ratios:
- 3:1 against the background for large text (14 pt bold, 18pt and up)
- 4.5:1 against the background for small text 

Additionally, you should be using visual cues and not just color cues. If you are trying to send an alert whether it is meant to contain an error or not, it is important to have other visual means of conveying a message. This can be done by using words or an icon near the error. Without these other cues, a person who is colorblind may not be able to differentiate between the error field and the fields without errors. 

Visual Accessibility

For people that are hard of hearing or deaf, it is important that sounds are able to be understood through other means. Often times, subtitles or a transcript are included for people that are hard of hearing.

Auditory Accessibility

Triggers for seizures:
- Screens due to the flicker or rolling images.
- Video games/videos/animations containing rapid flashes or alternating patterns of different colors.
- Intense strobe lights 
- Certain visual patterns, especially stripes of contrasting colors.

As designers, we should understand color and patterns that may cause seizures.
There are certain guidelines that can help especially if your design includes videos, gifs, or animations.

Seizure Accessibility

Individuals with learning disabilities have difficulty with language expression and comprehension. As a result, they rely more on non-verbal indicators to process information from others. 


Learning & Cognitive Accessibility  

People with mobility, circulatory, respiratory, or neurological disabilities use many kinds of devices for mobility. Advances in technology have given rise to new devices that some people with disabilities use as mobility devices, including many veterans injured while serving in the military.

- Wheelchairs
- Crutches, walkers
- Joysticks
- Head pointers
- Trackballs
- Eye- or head-trackers
- Augmentative and alternative communication (AAC)

Mobility

Accessibility can be categorized into several primary areas based on the specific needs of users. These include visual accessibility, auditory accessibility, mobility considerations, seizure accessibility, and learning and cognitive accessibility, as well as related design practices such as color theory for accessibility.

Pepperdine University

Rutgers University, Newark

Grinnell College

New York University

University of Michigan - Ann Arbor

Google

Ensuring that all people have the ability to utilize a product, facility, or service, regardless of any disability they may have. Accessibility may include the modification of existing infrastructure, products, or services or designing them with disabled users in mind.

Accessibility

Devices that help maintain or improve the functional capabilities and/or independence of individuals with disabilities.

Assistive Technology (ATs)

Accommodations refer to adaptations that are tailored to a specific individual's unique needs. Whereas, accessibility refers to design choices that are not created with a specific individual in mind but still attempt to make a product, service, or environment accessible to as many people as possible regardless of disability.
Accessibility is a more general approach while accommodations are a more individualized approach.

Difference between Accessibility and Accommodation

Accessibility is often difficult to measure or define, due to the many types of accessibility that exist. A structure may be accessible to someone with one type of disability, but not to someone with another. Additionally, there are many different criteria that can be used to determine or measure accessibility.

Challenges in Determining Accessibility

Captioning is the process of displaying text while a video is being played. Typically, the text will be a transcription of the video's audio, noting who is speaking along with sound effects and important musical cues. This helps to make films, television shows, and other video recordings accessible to those who are hard of hearing or deaf.

Captioning

Section 504 of the Rehabilitation Act (29 U.S.C. § 794) requires that the housing owner/landlord is required to pay for any accommodations as well as fix them. The exception is that if the person demonstrates that providing payment for this would be a burden. Section 504 and the ADA requires that governmental bodies will be financially responsible for accommodations for public housing and other federally assisted provided housing, 24 C.F.R. part 8, 24 C.F.R. part 9. 

Payment for Reasonable Accommodation

Created in 1973, the U.S. Access Board is a federal agency that serves to ensure accessibility in federally funded properties/buildings. The agency is responsible for determining accessibility standards when it comes to built environments, vehicles used for transportation, equipment in the medical field, tools for communicating, as well as IT. 

United States Access Board 

Audio Description is the process of narrating certain actions or details that are normally seen visually, such as what a character is wearing. This process is often provided with films, television shows, stage plays, museums to accommodate people with visual impairments. It is often provided via an alternate audio track on a DVD or a handheld audio player.

Audio Description

Disability, sexual orientation, gender identity, and mental health have a large impact on people's experience in the medical field within the context of health equity. Lived experience and differences should be placed at the forefront of this discussion. These four identities affect health equity through comorbidity and the experience of stigma (directly or indirectly). 

Health Inequity of Disability, Mental Health, Sexual Orientation, and Gender Identity

The COVID 19 pandemic impacted all people in profound ways, however, people with disabilities have been impacted more harshly and at a much higher level than people without disabilities. People of different disabilities were also impacted in varying ways. It is important to keep in mind that while these challenges are COVID specific, many of the remedies can be incorporated into daily life to make day to day living easier. 

Pandemic and Disability: Challenges Faced and Role of Technology

Children with disabilities are much more likely to need mental health support than their non-disabled peers. Despite this, children with disabilities are very rarely diagnosed with and receive treatment for mental health issues. 

Mental Health Services Use Among School-Aged Children with Disabilities

Around the world, one billion people live with disabilities. This report argues that these individuals are being left behind regarding health. Lack of access not only goes against the rights of people with disabilities under international law but also poses a challenge to achieving better health services for one billion people with disabilities, which is essential for achieving Universal Health Coverage (UHC) and Sustainable Development Goal 3. Most of these individuals are in low and middle-income countries and the poorest sections of society. People with disabilities encounter more obstacles in obtaining healthcare services and have less health coverage, leading to poorer health outcomes due to their higher healthcare needs.

Access to Healthcare

The Americans with Disabilities Act (ADA) of 1990 is a key piece of U.S. legislation that prohibits discrimination against individuals based on their disability. The law is founded on the principle that people with disabilities are capable of making valuable contributions to organizations. A central requirement of the ADA is that employers must provide reasonable accommodations to help employees with disabilities perform their jobs, so long as these accommodations do not cause undue hardship to the employer.

Americans with Disabilities Act (ADA) of 1990

This article examines how people with disabilities experience the design of public urban spaces in a social housing area in Aarhus, Denmark. Drawing on 14 universal design walks conducted with 17 participants, the study shows how ableist design practices create physical, mental, and social constraints in everyday life.

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