Limiting children to certain colors based on their gender is a bit stifling -- for girls and boys. Boys need access to pink... and fairy tales and art, just as much as girls need access to blue... and science and sports. Yet, gender labels limit our children into thinking that they can only wear/play/do/whatever it is that coincides with their gender, often leading them to question, or even mock, another child who's not conforming to these labels.
My husband and I teach our kids that all colors are for everyone because we're dealing with something more significant than colors. Gender labels may start with pink and blue, but they certainly don't end there. Gender labels spill over into playtime, school and even careers. Here's how we're squashing the sexism in our home:
- We provide nontraditional choices and encourage our children to play with/wear/do whatever is of interest. As appropriate, we give our children the full range of options and accept whatever choice is made. We never label their choice as a boy/girl choice; it's just their choice.
- We limit screen time and commercialization. Our kids don't have access to characters, shows, or movies that are violent or sexist.
- We correct the nonsense. If someone tells our children that "___ is only for girls" or "___ is only for boys," we show them how and why that's not true.
It is perfectly fine that some little boys love construction sites and some little girls love dollhouses, but that doesn't mean we should label their choice and then stop exposing them to different possibilities.
Sans labels and limitations, my 3 year old, Zachary, loves rainbows, Rosie the train, and his pink and purple dump truck. When it was time to buy Zachary's Keens, I asked him to choose the color. He chose purple. Zachary is the proud wearer of purple Keens. He loves them and shows them off to anyone willing to look and listen. 
At the park, Zachary asked his routine question to a four-year-old girl, "Do you like my Keens?" She responded with, "Purple is only for girls!" Zachary looked down at the sandbox. I cheerfully jumped in with, "Actually, purple is for everyone." The little girl asserted back, "That's not true, purple and pink are only for girls!" I smiled and shook my head, "No, purple and pink are for everyone." The young girl insisted, "No! Only girls can wear purple!"
Clearly, I was not going to win this argument.
A couple days later at the pediatrician's office, the nurse asked my son to choose a sticker for himself. As he reached for a sticker, the nurse said, "oh no honey, those stickers are for girls, here look at these, these stickers are for boys."
My son shouldn't have to feel badly about wearing certain colors or choosing certain stickers. No child should be made to feel badly about what they're wearing or what they like.
There is more at stake here than sandals and stickers. This is about raising tolerant children. This is about children feeling confident, rather than worrying about being judged or mocked. To empower our girls and nurture our boys, we need to ensure that they each have access to all of the possibilities available to the other. To raise open-minded, whole children, we need to provide open-minded, whole experiences.
This means that we need to nurture our children as children, instead of labeling and limiting them and their choices. Let's start by teaching our children that gender is not a limitation. Let's stop the mocking that happens when a child wears or does something unconventional. Let's get comfortable with girls wearing football jerseys and boys wearing hot pink. And please, let's teach our children that all colors are for everyone.