Highlight one specific flow. (2 flows leaving from one node)

[ZheFrench]

I have a node with two flows to two different next nodes. VEGFC -> NRP2 / VEGFC -> ITGB1

I want to color one flow only.

scale_fill_manual(values = c('VEGFC' = "red",NRP2="red")

But this will color also VEGFC -> ITGB1.
I want to have only VEGFC -> NRP2 colored in red.

The following give a concrete example. Is this possible ? Tks.

https://github.com/ZheFrench/pics/blob/master/GSE69667.TPMs.EMT.A549.HSapiens.TimeCourse.Rep1.csv_SANKEY.png?raw=true

[bdidds2]

I'm very interested in this as well. flow.fill doesn't seem to be able to color specific flows.