Using R corrplot, I have not found a solution where the correlation coefficients in the boxes are plotted together with their significances, i.e. 0.84\*\*\*
Here is the code plotting only the significance stars. How can the correlation coefficients be added there?

```
M<-cor(mtcars)
res1 <- cor.mtest(mtcars, conf.level = .95)
corrplot(cor(mtcars),
     method="square",
     type="lower",
     p.mat = res1$p,
     insig = "label_sig",
     sig.level = c(.001, .01, .05),
     pch.cex = 0.8,
     pch.col = "red",
     tl.col="black",
     tl.cex=1,
     outline=TRUE)

```

If I add, as by the first answer suggested, addCoef.col = "black",
the text overlays the significance stars so they cannot really be seen anymore:
[![enter image description here](https://i.stack.imgur.com/IYc69.png)](https://i.stack.imgur.com/IYc69.png)