Variable contrasting_color isn't created for specific background colors

[hy6-2]

I was trying to render a graph (render_graph()) and encountered an error that says:

Error in `dplyr::mutate()`:
ℹ In argument: `value_x = contrasting_text_color(background_color = value)`.
Caused by error in `contrasting_text_color()`:
! Object 'contrasting_color' doesn't exist.

And as I looked into the function contrasting_text_color(background_color) in utils.R (line 451-475), I found the variable contrasting_color wouldn't be created in the case when saturation < 0.35 & luminance <= 0.5, according to the conditions described in line 466-472. For my case, I was using "gray40" as the background_color, which matched the exception and caused the error.
Could you please revise the code? Thank you very much for your supports in advance!