I have this dataframe that I'm trying to make a vertical line on an x-axis that is categorical.

```
data <- data.frame(
  condition = c('1', '1', '1', '1', '1', '2', '2', '2', '2', '2', '3', '3', '3', '3', '3'),
  AssessmentGrade = c('400', '410', '420', '430', '440', '500', '510', '520', '530', '540', 
                      '300', '310', '320', '330', '340'), 
  Freq = c('1', '2', '1', '5', '7', '9', '1', '5', '3', '4', '5', '8', '1', '3', '5'), 
  MathGrade = c('A+', 'B-', 'C-', 'D', 'F', 'A-', 'B', 'C+', 'D-', 'F', 'A+', 'D', 'D', 'F', 'C'), 
  Condition = c('Condition 1', 'Condition 1', 'Condition 1', 'Condition 1', 'Condition 1', 
                'Condition 2', 'Condition 2', 'Condition 2', 'Condition 2', 'Condition 2', 
                'Condition 3', 'Condition 3', 'Condition 3', 'Condition 3', 'Condition 3'))

```

I tried adding a field to make grade numeric and that helped

```
data$Gradenum <- as.numeric(data$MathGrade)

```

I used ggplot to get abubble graph but I was wondering how I would edit it to use my company's standard colors

```
p <- ggplot(data, aes(x = MathGrade, y = AssessmentGrade, size = Freq, fill = Condition)) +
 geom_point(aes(colour = Condition)) +
 ggtitle("Main Title") +
 labs(x = "First Math Grade", y = "Math Assessment Score")

```

How can I get a vertical line between C+ and D? I see a lot of information out there if your x axis is a date but not for other categorical values