I am trying to change the color for the individual 'Years' variable on this plot. So far I have this code:
x <- ggplot(elect, aes(x = `Congressional Spending`, y = `United States VEP Midterm Turnout Rate`, color = Year)) +
geom_point() + geom_smooth(method = lm, col = 'purple', size = 0.5)

I also tried using:
scale_color_manual(values = c("red", "yellow",
"blue", "orange",
"green", "black"))
Error: Continuous value supplied to discrete scale
