How outrageous of you, op, to decline to dress your child according to the male uniform he must wear for the rest of his life.
shock factor
If a male child wearing pink shocks you then there is something very seriously wrong with you.
So many of the posts on this thread are extremely depressing and lacking in any kind of critical thought process. The rules that pink, sparkly supposedly feminine things like flowers are for girls, and blue, dull, supposedly masculine things like cars are for boys, are both fashions in our culture. Nothing more. They're not universal rules across all cultures and all times. Pink used to be considered a boy's colour, and blue for girls.
In much the same way that white used to be a colour worn at funerals, and only became fashionable as a colour for wedding dresses after queen Victoria.
They are our culture's current fashions, underwritten by sexism and homophobia. Everybody who defends those stereotypes and attacks people prepared to live outside them, bears responsibility for how hard life can be for people who don't fit into those boxes. You create an environment where bullying and ostracising people who are gay is normalised and accepted.
Clothing should never be the difference between people accepting and respecting you, or mistreating and excluding you.
The clothes you wear don't make you gay or straight. They don't make you male or female.
If you think they do and you also think it's ok to force those expectations on your own children or other people - whether by silently judging or openly criticising - then you are the one with a very damaging problem and you need to go away and take a good look at yourself.