In my plot, I can’t get my scale_fill_manual to appropriately assign the “lightblue” to the non-active data points, but I have no issues with assigning “lightcoral” to the active point data. Also, I can’t get the labels for the point labels to update properly.

My code:

ylim.prim <- c(0,850) # scale for precipitation
ylim.sec <- c(-15,20) # scale for mean temperature

b <- diff(ylim.prim)/diff(ylim.sec)
a <- ylim.prim[1] - b*ylim.sec[1] 

 ggplot() + theme_bw() +
  geom_bar(data=precip, mapping=aes(x=Year, y=Value, fill=Variable), stat="identity", position="dodge", color="black") +
  geom_point(data=temps, aes(x=Year, y=a+Value*b, color=Variable), size=5, shape=18) +
  
  # Borders for point data
  geom_point(data=temps, aes(y=a + Value*b, x=Year), color="black", size=3, shape=5, stroke=2) +
  
  # Update scale
  scale_y_continuous(name="Total Precipitation (mm) n", 
                     breaks=c(0,100,200,300,400,500,600,700,800,900), 
                     limits=c(0,900),
                     expand=c(0,0), # to make the bars start at the x-axis
                     sec.axis = sec_axis(~(. - a)/b, name = "Mean Temperature  (°C)")) +
  scale_x_continuous(name="nYear") +
  theme(axis.text.x = element_text(size=15, colour="black"),
        axis.text.y = element_text(size=15, colour="black"),
        axis.title = element_text(size=15),
        axis.title.y = element_text(size=15),
        legend.text = element_text(size=15),
        legend.title = element_text(size=15),
        axis.ticks = element_line(linewidth=1),
        axis.title.y.right = element_text(angle=90)) +

 # Assign color and labels to legend
  scale_fill_manual(labels=c("Active","Non-Active","Active","Non-Active"),
                    values=c("lightcoral","lightblue","lightcoral","lightblue"),
                    name=c("Precipitation","Temperature"))

> dput(precip)
structure(list(Year = c(2020L, 2020L, 2021L, 2021L, 2022L, 2022L, 
2023L, 2023L), Variable = c("Precip.x", "Precip.y", "Precip.x", 
"Precip.y", "Precip.x", "Precip.y", "Precip.x", "Precip.y"), 
    Value = c(737, 805, 789.8, 612.8, 611.3, 710.5, 802.7, 753.5
    )), row.names = c(NA, -8L), class = c("tbl_df", "tbl", "data.frame"
))

> dput(temps)
structure(list(Year = c(2020L, 2020L, 2021L, 2021L, 2022L, 2022L, 
2023L, 2023L), Variable = c("Temp.x", "Temp.y", "Temp.x", "Temp.y", 
"Temp.x", "Temp.y", "Temp.x", "Temp.y"), Value = c(17.081043956044, 
3.2175, 17.6239554317549, 3.48527777777778, 17.1328402366864, 
1.54847645429363, 17.3330578512397, 3.79614325068871)), row.names = c(NA, 
-8L), class = c("tbl_df", "tbl", "data.frame"))

My plot. The blue geom points aren’t the correct blue, but the red seems to be the “lightcoral” that I want. I want the point colors to match the bar colors. And the titles in the legend don’t seem to update for the geom point data.