Yes they need to be cleaned up. Columbian Wyandottes showing excess of color are defects which are not countenanced in exhibition poultry but are useful in breeding to strengthen the black in the hackle, saddle and tail in strains that are weak in that respect. A white under-color in the back is rarely found in combination with the right quality of black in the neck, wings and tail.
I can see this with chicks I am growing out. The ones born mostly white look clean but the hackles are lacking color and definition. But the darkest chicks are dirty looking. I need to find the right balance of the two. Maybe next year.