help me with my ggplot - Githubissues

I am trying to make a geomplot using ggplot. then I met this error，why this color not blue:

knitr::opts_chunk$set(echo = TRUE)
library(ggplot2)
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
data(mpg)

mpg %>% 
  ggplot() + 
  geom_point(aes(x = displ, y = hwy), color = "blue")

^{Created on 2020-08-13 by the reprex package (v0.3.0)}

Session info

``` r devtools::session_info() #> ─ Session info ─────────────────────────────────────────────────────────────── #> setting value #> version R version 4.0.2 (2020-06-22) #> os macOS Catalina 10.15.5 #> system x86_64, darwin17.0 #> ui X11 #> language (EN) #> collate en_AU.UTF-8 #> ctype en_AU.UTF-8 #> tz Australia/Melbourne #> date 2020-08-13 #> #> ─ Packages ─────────────────────────────────────────────────────────────────── #> package * version date lib source #> assertthat 0.2.1 2019-03-21 [1] CRAN (R 4.0.2) #> backports 1.1.8 2020-06-17 [1] CRAN (R 4.0.2) #> callr 3.4.3 2020-03-28 [1] CRAN (R 4.0.2) #> cli 2.0.2 2020-02-28 [1] CRAN (R 4.0.2) #> colorspace 1.4-1 2019-03-18 [1] CRAN (R 4.0.2) #> crayon 1.3.4 2017-09-16 [1] CRAN (R 4.0.2) #> curl 4.3 2019-12-02 [1] CRAN (R 4.0.1) #> desc 1.2.0 2018-05-01 [1] CRAN (R 4.0.2) #> devtools 2.3.1 2020-07-21 [1] CRAN (R 4.0.2) #> digest 0.6.25 2020-02-23 [1] CRAN (R 4.0.2) #> dplyr * 1.0.1 2020-07-31 [1] CRAN (R 4.0.2) #> ellipsis 0.3.1 2020-05-15 [1] CRAN (R 4.0.2) #> evaluate 0.14 2019-05-28 [1] CRAN (R 4.0.1) #> fansi 0.4.1 2020-01-08 [1] CRAN (R 4.0.2) #> farver 2.0.3 2020-01-16 [1] CRAN (R 4.0.2) #> fs 1.5.0 2020-07-31 [1] CRAN (R 4.0.2) #> generics 0.0.2 2018-11-29 [1] CRAN (R 4.0.2) #> ggplot2 * 3.3.2 2020-06-19 [1] CRAN (R 4.0.2) #> glue 1.4.1 2020-05-13 [1] CRAN (R 4.0.2) #> gtable 0.3.0 2019-03-25 [1] CRAN (R 4.0.2) #> highr 0.8 2019-03-20 [1] CRAN (R 4.0.2) #> htmltools 0.5.0 2020-06-16 [1] CRAN (R 4.0.2) #> httr 1.4.2 2020-07-20 [1] CRAN (R 4.0.2) #> knitr 1.29 2020-06-23 [1] CRAN (R 4.0.2) #> labeling 0.3 2014-08-23 [1] CRAN (R 4.0.2) #> lifecycle 0.2.0 2020-03-06 [1] CRAN (R 4.0.2) #> magrittr 1.5 2014-11-22 [1] CRAN (R 4.0.2) #> memoise 1.1.0 2017-04-21 [1] CRAN (R 4.0.2) #> mime 0.9 2020-02-04 [1] CRAN (R 4.0.2) #> munsell 0.5.0 2018-06-12 [1] CRAN (R 4.0.2) #> pillar 1.4.6 2020-07-10 [1] CRAN (R 4.0.2) #> pkgbuild 1.1.0 2020-07-13 [1] CRAN (R 4.0.2) #> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.0.2) #> pkgload 1.1.0 2020-05-29 [1] CRAN (R 4.0.2) #> prettyunits 1.1.1 2020-01-24 [1] CRAN (R 4.0.2) #> processx 3.4.3 2020-07-05 [1] CRAN (R 4.0.2) #> ps 1.3.4 2020-08-11 [1] CRAN (R 4.0.2) #> purrr 0.3.4 2020-04-17 [1] CRAN (R 4.0.2) #> R6 2.4.1 2019-11-12 [1] CRAN (R 4.0.2) #> remotes 2.2.0 2020-07-21 [1] CRAN (R 4.0.2) #> rlang 0.4.7 2020-07-09 [1] CRAN (R 4.0.2) #> rmarkdown 2.3 2020-06-18 [1] CRAN (R 4.0.2) #> rprojroot 1.3-2 2018-01-03 [1] CRAN (R 4.0.2) #> scales 1.1.1 2020-05-11 [1] CRAN (R 4.0.2) #> sessioninfo 1.1.1 2018-11-05 [1] CRAN (R 4.0.2) #> stringi 1.4.6 2020-02-17 [1] CRAN (R 4.0.2) #> stringr 1.4.0 2019-02-10 [1] CRAN (R 4.0.2) #> testthat 2.3.2 2020-03-02 [1] CRAN (R 4.0.2) #> tibble 3.0.3 2020-07-10 [1] CRAN (R 4.0.2) #> tidyselect 1.1.0 2020-05-11 [1] CRAN (R 4.0.2) #> usethis 1.6.1 2020-04-29 [1] CRAN (R 4.0.2) #> vctrs 0.3.2 2020-07-15 [1] CRAN (R 4.0.2) #> withr 2.2.0 2020-04-20 [1] CRAN (R 4.0.2) #> xfun 0.16 2020-07-24 [1] CRAN (R 4.0.2) #> xml2 1.3.2 2020-04-23 [1] CRAN (R 4.0.2) #> yaml 2.2.1 2020-02-01 [1] CRAN (R 4.0.2) #> #> [1] /Library/Frameworks/R.framework/Versions/4.0/Resources/library ```

etc5523-2020 / exercise2C

help me with my ggplot #28