style(p, ..., traces = NULL)

# style() is especially useful in conjunction with ggplotly()
# It allows you to leverage the underlying plotly.js library to change 
# the return result of ggplotly()
(p <- ggplotly(qplot(data = mtcars, wt, mpg, geom = c("point", "smooth"))))

# removes hoverinfo for the line/ribbon traces (use `plotly_json()` to verify!)
style(p, hoverinfo = "none", traces = c(2, 3))

# another example with plot_ly() instead of ggplotly()
marker <- list(
  color = "red",
  line = list(
    width = 20, 
    color = "black"
 )
)
(p <- plot_ly(x = 1:10, y = 1:10, marker = marker))

# note how the entire (marker) object is replaced if a list is provided
style(p, marker = list(line = list(color = "blue")))

# similar to plotly.js, you can update a particular attribute like so 
# https://github.com/plotly/plotly.js/issues/1866#issuecomment-314115744
style(p, marker.line.color = "blue") 
# this clobbers the previously supplied marker.line.color
style(p, marker.line = list(width = 2.5), marker.size = 10)