Is it possible to set the node colors in a Sankey diagram?

Using for example,

```mermaid
---
config:
  sankey:
    showValues: true
    linkColor: gradient
    nodeAlignment: justify

---
sankey-beta

%% source,target,value
foo,a,100
foo,b,10
foo,c,20
b,c,10
d,c,15
```

Can I choose colors?