Why can't I add color using col = in my cat_plot?

Question

Figure 1 I am trying to make the lines in my cat_plot color blue. I have tried the following code, putting the col = next to the geom = c("line"):

library(interactions) 
Figure01 <- cat_plot(M1, pred = "OA_status", geom = c("line", col = "blue"), interval = TRUE, 
        x.label = 'OA Status', y.label = 'Predicted Altmetric Score', 
        main.title = 'Figure 1')
Figure01

But I am only getting the attached picture. As you can see, the lines are not blue in this plot. Where am I going wrong— is the col = in the wrong place? Or is the color argument not applicable for this type of plot?