Hi,
I'm making gheatmap with continuous values except some of the values are NA.
When I set the two colours for low and high, the cells with NA are white as I wish.

But when I use a colour scale as below since I want more colours on heatmap, the NA cells are coloured as grey.

If I colour all the cells as white with scale_fill_gradientn(colours = "white"), those NA cells are still grey.
I've tried to change the panel and plot background but it doesn't change.
So, how can I leave NA cells as white if I want to use a colour scale?