That may be true that a century ago baby girls and baby boys in the US were associated with different colors than today, but the reasoning of "pink, being a more decided and stronger color" seems suspect to me. How come dozens of flags of countries around the world feature the color blue and approximately none feature pink (Spain and Mexico have a small amount of pink in their coats of arms). When it came down to it, the designers of the Union Jack and the Stars and Stripes and all of the Tribands, etc ... none of them thought, "yeah, lets add some pink to project strength".

Baby clothes use more faded colors because of the frequent washing, so it's pink or light blue. Many countries use red in their flags.

Most flags that have blue don't have sky blue, they have a darker blue. If pink was as dark it would be red.