tbh if your DS is surrounded by blue then it's highly unlikely that when he gets to choose, he's going to opt for different colours.
With all due respect APlace that is just incredible nonsense.
I have boy/girl twins. We were bought a lot of clothes in their early days. Piles and piles of pink and blue. Not my particular taste but they were kindly given and so we used them.
The clothes buying levelled off once the Grandparents could buy interesting toys for them. Around about age 3 when my two started expressing a preference regarding clothes.
Both of my two pick a broad range of colours in clothes. DS's favourite colour is currently purple, while DD favours turquoise.
The fact they spent the first 2.5 years of their lives almost exclusively in blue and pink is completely irrelevant.