Contrast requirements for WCAG level A?

Question

I am trying to adapt an older website to become accessible. However, the first tests with browser tools like "WAVE" showed me contrast errors for headers which are simply colored text on white background. The colors are #97CB44 (a lighter green) and #EC7F38 (orange). The background, as I wrote, is #FFF.

However, these colors are an essential part of the client's corporate identity and logo - I cannot / must not change them.

I wondered about the corresponding WCAG 2.0 guidelines. All I can find (also on other websites) is this rule being quoted (which originally can be found here: https://www.w3.org/TR/WCAG20/#visual-audio-contrast):

1.4.3 Contrast (Minimum): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following: (Level AA)

Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;

Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.

Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.

Now, judging from the end of the first paragraph, this seems to be the prerequisite for level AA, which I not necessarily need to meet - level A would be sufficient in my case.

But I don't understand what is necessary for level A concerning contrast? Are there no contrast rules at all for level A, so would my website (with the text colors desribed above) validate as level A?

Answer 1

WCAG 2.0 doesn’t define any contrast requirements for level A.

The only guidelines about contrast are:

• 1.4.3 Contrast (Minimum) for level AA.

• 1.4.6 Contrast (Enhanced) for level AAA.

Rationales for the chosen ratios: for 1.4.3 and for 1.4.6. Both rationales refer to the minimum level of 3:1, which is recommended by other sources, but it’s not a WCAG guideline.

Answer 2

But I don't understand what is necessary for level A concerning contrast? Are there no contrast rules at all for level A, so would my website (with the text colors desribed above) validate as level A?

There's no contrast minimum set for the A level. This implies that your website won't be accessible to a large part of the population.

Many legislations require meeting the level AA. Risk of lawsuit still exists if you do not respect the level AA.

Read for instance Karl Groves article about Understanding WCAG Level which leads to that same conclusion : no matter if you want to meet A or AA level, you have to be accessible.

However, these colors are an essential part of the client's corporate identity and logo - I cannot / must not change them.

The question is not whether the colors are part of the logo, but if the text is not dissociable from the logo itself.

For instance, if your logo contains orange (#EC7F38) and you want to use the same orange for the baseline, the baseline is not part of the logo.