Why is Pink a Girl Color and Blue a Boy Color'
'According to the website 'Gender Specific Colors,' it would seem that assigning color to gender is mostly a 20th century trait. It would also seem that at one time, the color associations were reversed when color first came into use as a gender identifier. . . .
'There has been a great diversity of opinion on the subject, but the generally accepted rule is pink for the boy and blue for the girl. The reason is that pink being a more decided and stronger color is more suitable for the boy, while blue, which is more delicate and dainty, is prettier for the girl.' [Ladies Home Journal, June, 1918]'
'from 11 Great Colour Legends, at COLOURlovers.com. Click here for the whole article.

I have some baby clothes worn by my father (your grandfather, born 1902) which have remnants of pink ribbon. When I showed them to the textile experts at the North Carolina Museum of History, they told me that pink was for boys in those days.
It?s a topsy-turvy world. But . . . don?t we also have a baby picture of him in a dress?