At one time if a man wearing a pink shirt it would immediately be assumed that he was gay but now it is perfectly acceptable. It's true that pink is normally associated with women but a pale pink shirt can look very stylish underneath a grey or dark suit.
Some men may not be comfortable wearing pink even now because some people still associate it with being effeminate but this attitude is disappearing. Men's fashions now include pink clothing as manufacturers recognize that this is a color that can be worn by men and women alike and look very stylish.
Attitudes towards men wearing pink shirts can vary depending on cultural and individual perspectives. In both the UK and the USA, societal attitudes have evolved over time, and many people now view fashion choices, including colors, as a personal expression of style rather than a strict gender norm.
In general, wearing a pink shirt today is often seen as a fashion choice rather than a statement about one's masculinity. Many people appreciate individuals who confidently wear pink or other traditionally "feminine" colors, as it challenges outdated gender stereotypes and promotes inclusivity.