You may already know that your fingernails and stool can reveal a lot about how healthy you are. But it turns out that some health issues can show up on your tongue, too. Certain conditions can change its colour and even its texture.According to the health information site Medical News Today: “Changes in tongue colour can indicate an underlying health issue, such as an infection.” Sometimes, the signs can point to something serious, they add ― for instance, a blue tongue can reveal very low oxygen.What does my tongue colour say about my health?Healthy tongues usually look pink and not too pale, the site says. Here’s what other colours may be symptoms of, per Medical News Today:1) Blackdrinking coffee and teararely, diabetes or HIVbad oral hygiene