How can I assign a color range to edges in igraph plot in R based on edge attributes?

I have a large social network plot that I am trying to color-code using the strength of the connections between individuals. In mock_table, the individuals are listed in column a and b, and the strength of each connection is given in column c.

I was successful in properly assigning these strength values to the edge.width function, however, when I attempt to apply this to the edge.color, the values do not properly align. The colors in the plot do represent sn_color, but they are not assigned to the proper edges. The thickest edges (strongest connection, largest c-value) should also have the darkest color and vice versa.

Below is a simplified version of my current code:

mock_table <- as.data.frame(cbind(a=c("PO", "BL", "MA", "AL", "BL"), b=c("MA", "BO", "ED", "MA", "MA"), c=as.numeric(c(8,41,10,23,50))))
mock_table$c <- as.numeric(as.character(mock_table$c))

sn_graph <- graph_from_data_frame(d=mock_table, vertices = c("PO", "BL", "MA", "AL", "BO", "ED"), directed = FALSE)
sn_proximity <- (mock_table$"c")

sn_colorrange <- colorRampPalette(c("yellow", "orange", "red", "darkred"))
sn_color <- sn_colorrange(length(sn_proximity))

plot(sn_graph,
     edge.width=(1/3)*(sn_proximity),
     edge.color=sn_color
     )

Would anyone be able to help me figure out how I can properly assign this color palette? Thanks so much!

Edited to include reproducible example code.

Solution

You need to tell the plot exactly which color to use. If you wanted to use a different color for each from the ramp, then you could do something like

plot(sn_graph,
     edge.width=(1/3)*(sn_proximity),
     edge.color=sn_color[order(sn_proximity)]
)

Otherwise it may be more common to set a fixed number of bins and then use cut() to the color has more meaning

n_bins <- 5
sn_color <- sn_colorrange(n_bins)
plot(sn_graph,
     edge.width=(1/3)*(sn_proximity),
     edge.color=sn_color[cut(sn_proximity, breaks=n_bins )]
)