Is there a way to make colour heat maps also interpretable in grey scale?

Viridis or other accessible color ramps for figures can be used when possible. It is an addition to R that can be downloaded from the below link

https://cran.r-project.org/web/packages/viridis/vignettes/intro-to-virid...

Viridis color ramps are not only aesthetically very nice, they are designed to still be interpretable when printed in greyscale, and are interpretable to end users with various types of color blindness. You can make your figures prettier AND more accessible to people with disabilities just by adding a call to viridis.