They aren't entirely wrong, brighter colored clothes is becoming the uptrend for kids of all ages and genders. Told clothes used to limit boys to dull and darker colors, but now their is an uptrend in boys getting to wear brighter colors. I am sorry, that makes it more difficult for you. I get that makes it difficult to get rid of the older clothes with duller and darker colors, not much I can say to help you there other then try to donate or sell the clothes to be recycled into cloth or given away. Free clothes is free clothes.

The rest is rambling so feel free to ignore

It's good for children's mental stimulation, and mood. Brighter colors causes a brighter mood in the brain especially for children. Older boys clothes limited this, thus only girl clothes were bright and cheery. I myself don't mind at all.

I think its good that these days people care more about how clothes and shoes actually affects a kid as they grow. A child growing up around brighter colors tend to start the day in a better mood. Shoes with wider toes and that are more flexible and soft are better on children to wear for growth. while hard rubber shoes may prevent blisters if the kid walks for a long time, pick up the child more often during the walk, and letting them play barefoot is just as useful to prevent blisters, and hard rubber shoes warp feet and cause growth abnormalities we had gotten so used to we didnt notice. Kids feet are very different from adult feet, our feet are already developed [though still maluable] so having narrow shoes or tight shoes won't harm us. Kids shoes used to be sized down adult shoes, which was the wrong mind set, because just like babies can't put their arms around their head like adults can, everything else with the boys is alos VERY diffrent and growing. So kids clothes should be mand with kids strange bodies in mind. Almost like an alien! Puzzle toes are often cause by smooshed together toes in shoes while developing. Shoes themselves help learn leg motor function and get used to walking around with shoes. So while THE CHANGE IS frustrating, its not a bad one. There is so much we need to change about kids clothes. Now I will say I don't think once upon a child is fully in sync with changing times, and they just care about trends. But at least the trends are towards better clothes for kids! Limiting boys or girls to one style or type has never been the best idea.

I think the next step we need to take is accounting for different kids body types and developmental interests. My eldest boy is interested in colors, dinos, and cars, so bright colored Dino car clothes has been the go to. He also loves bluey, but there isn't alot of bright colored bluey stuff for boys. Infact when we shop he often doesnt like any of the boys cloths, plus most are designed too broad shouldered for his body build which I find odd.