Make careful and sparing use of colour. Three is the magic number here, with designers advising that no more than three core colours should be used.
For readability, select muted colours for backgrounds such as pale beige or cream. Ensure that there is strong contrast between background and foreground ie one is dark and the other is light.
Blackboard Learn has a text colour swatch of just 40 colours by default but click on More Colours for increased choices.
Keep in mind that those with vision difficulties such as colour blindness may have problems with certain colours. Always check that the background colour and the text colour have enough contrast so that the text remains readable to someone with vision problems.
Contrast is particularly important for vision-impaired users, however, all users will benefit from greater readability.
Although the use of colour is another option for differentiating type, coloured text, like underlining, has a special functional meaning in web documents. You should avoid putting coloured text within text blocks because readers will assume that the coloured text is a hypertext link and click on it. Avoid using colours close to the default web link colours of blue and violet.
Use WebAIM’s web tool to test colour contrast:
Or use the online Vischeck tools to see how your content would look to someone who has colour blindness: