Alpha error in Legend?

[cool.abbecker]

ggplot(
)  +
  geom_bar(
    width=1,
    dat=subset(temp,variable=="spec_h_blast1"),
    aes(x=fam,y=value,fill=variable),
    stat="identity",
    position="identity",
    color="black"
  ) +
 etc ....................
  ) +
  scale_fill_manual(
    name=NULL,
    labels=NULL,
    values=c("#6a4a3c",alpha("#6a4a3c",0),"#00A0B0",alpha("#00A0B0",0.1),"#EDC951",alpha("#EDC951",0.1))
) +
  theme(
  legend.position = c(0,.5),
  legend.justification = c(1,1),
  legend.key=element_blank()
)

Works ... but looks shitty

If I set apha to 0.5, the legend becomes unreadable.   values=c("#6a4a3c",alpha("#6a4a3c",0),"#00A0B0",alpha("#00A0B0",0.5),"#EDC951",alpha("#EDC951",0.5))
The alpha level in the legend seems to be different from the plot.
I did not ever set the parameter alpha anywhere else in the ehole plot.

Known bug?

[cool.abbecker]

Still not sure what is going on, but

  guides(
    fill=guide_legend(nrow=2,override.aes = list(alpha = c(1,0.25,1,0.1,1,0.1)))
  )

produced the results I was looking for. Although this should not be necessary.