How do I color edges and vertices in igraph?

I have a large data set that I want to represent with a network graph using igraph. I just don't understand how to get the colors right. My data is in this format:

df <- data.frame(name = c("john", "john", "john", "linda", "linda", "daniel"), answer = c("linda", "sam", "anna", "john", "sam", "anna"), location = c("#000000", "#000000", "#343434", "#000000", "#000000", "#343434"), group = c("#00FF00", "#00FF00", "#00FF00", "#FF0000", "#FF0000", "#FF0000"))

+--------+--------+----------+---------+
|  name  | answer | location |  group  |
+--------+--------+----------+---------+
| john   | linda  | #000000  | #00FF00 |
| john   | sam    | #000000  | #00FF00 |
| john   | anna   | #343434  | #00FF00 |
| linda  | john   | #000000  | #FF0000 |
| linda  | sam    | #000000  | #FF0000 |
| daniel | anna   | #343434  | #FF0000 |
+--------+--------+----------+---------+

This represents the results of an interview. Everyone got the same question, and then had to give the answer to that question in the form of a name (or multiple names). So John answered "linda, sam, and anna", linda answered "john and sam" and so on.

Now I would like to represent these results color coded in a network graph. The color in the column "group" is the color of the vertex of each person (so john is green and linda and daniel are both red). The color in the column "location" is the color of the arrow that goes from the vertex of "name" to the vertex of "answer". For example:

Here the arrows are right, but the colors are wrong. The two arrows between john and linda are supposed to be the same color. The vertice of john is supposed to be green, and the vertices of linda and daniel are supposed to be red. for sam and anna i have not set a color (how would i do that?)

My code so far is:

g <- graph.data.frame(df)
V(g)[df$answer]$color <- df$location
V(g)[df$name]$color <- df$group
plot(g, vertex.color = V(g)[df$name]$color, edge.color = V(g)[df$answer]$color)