pch and col function not working in R using Power BI

Hi All,

Below is the plot function I am using to plot 2 columns where one is date range and other one is Numeric. 



I am getting the plot as desired but now I want to know 2 more things : -

1) Can anyone help me with why pch and col functions are not working in this plot. (highlighted below in red)

2) Can I get rid of the hh:mm:ss from the date range on my plot in X axis.

Thanks,

Abhishek