Choosing an appropriate colour scheme for a website is vital, as an appropriate colour can improve the accessibility of a website to a visually impaired user. While an inappropriate colour scheme can make the website completely inaccessible, as the web developer may have chosen a colour scheme that makes it difficult for a visually impaired user to read the information or a web page or to distinguish between foreground and background information.
In order for a web page to be accessible to visually impaired user they must be able to easily distinguish between foreground and background information. The web developer can make there website more accessible to visually impaired users by choosing two contrasting foreground and background colours, such that a visually impaired user can easily distinguish between the foreground and background information on a web page. This information could be anything text, links, form labels, table heading etc.
Whether or not a visually impaired user is able to distinguish between foreground and background information on a matter is a matter of human judgement on the part of the web developer. This can be very difficult for a web developer to judge and there are very few tools available to assist the web developer in there judgement of this. There are a number of good articles on the lighthouse website. SSB Technologies has a piece of software called InFocus, which is able to check foreground and background colours for their “closeness” to each other. More information about InFocus can be found on the SSB Technologies website. It may also be useful for the web developer to get some feedback from visually impaired users about this issue.
It is not recommended that colour alone be used to convey information e.g. on a form it may say “all fields highlighted in red are mandatory.” Major screen readers such as Jaws and Windows-Eyes and major talking browsers such as IBM’s HomePage Reader cannot detect colours, so a blind user using a screen reader would not know which fields were highlighted in red. Colour can be used to convey information but it should not be used alone. So some other method should be used alongside colour such as an asterisks e.g. “all fields highlighted in red and marked with an * are mandatory.” This would make the form accessible to a blind user using a screen reader because screen readers are able to easily detect the asterisks character.