Omloop Het Nieuwsblad, the colour of the last two sections are a very dark red (probably not helped by the many vertical black lines and the narrowness of the coloured band), and could be mistaken for a possible brown (mountain section) rather than cobbles (red), particularly if somebody doesn't have the benefit of supporter status. Noticing this, I then noticed that the colours of mountain & cobbles sections on different races were not standard, and very from light/dark, and varied shading.
As such, I'd recommend a standardisation of colours, light brown for mountain, light/mid red for cobbles, etc, so it's visually clear what each section in every race is.
