Pontifications

As of dplyr 0.2 (I think) rowwise() is implemented, so the answer to this problem becomes:
  • abstract code:
tibble_to_apply_function_to %>% 
rowwise() %>% 
mutate(new_column = some_function(
some_column(s)_of_tibble_to_apply_function_to))
average_colour_ig_van_jan2016_with_colourname =  
  average_colour_ig_van_jan2016 %>% 
    rowwise() %>% 
       mutate(colourname = tc(colour))