# Fix: error bar colors now match curve colors

[bjreisman]

Fix error bar colors to match curve colors in plot.drc

Problem
When using plot.drc() with type = "bars", error bars are always black regardless of the col argument.

Solution
Error bars now inherit curve colors by default. Added errbar.col parameter for manual control.

library(drc)
model <- drm(DryMatter ~ Dose, Herbicide, data = S.alba, fct = LL.4())

# New default - error bars match curves
plot(model, type = "bars", col = c("red", "blue"))

# Old behavior - black error bars  
plot(model, type = "bars", col = c("red", "blue"), errbar.col = "black")