Is it a big ask for my wedding?

I’m not having a bridal party but I am asking my immediate family to wear a color scheme for my wedding! Everybody has said yes and they have all been a fan of the colors (blush pink and sage green) except…. while my father agreed to the color scheme he does not want to “make” his wife (of one year) wear the color. He said he’ll tell her if she finds a dress that color to wear it but if not then just wear whatever she finds. I’m not okay with that because I don’t think it’s that hard colors to find a dress when they have 6+months notice. I would be quite disappointed if she showed up in a random color. I have nothing against his wife but I think it would definitely cause friction. What are your thoughts?
Is it a big ask for my wedding?
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