bs_vars_file(input_file)

my_vars <- file.path(tempdir(), "custom-vars.scss")
my_theme <- file.path(tempdir(), "theme.css")

# Open template and edit variables
use_vars_template(
  output_file = my_vars,
  theme = "flatly"
)

# Create new theme based on the modified template
create_theme(
  theme = "flatly",
  bs_vars_file(input_file = my_vars),
  output_file = my_theme
)


# Clean up
unlink(my_vars)
unlink(my_theme)