Since it is possible to change clothes several times during a family photo shoot, you could even have several sets of clothes.
I recommend that the sets of family members harmonize with each other. This means that you should prepare clothes with a similar composition in terms of colors and materials.
There are colors that I do NOT recommend: black, because it darkens the mood of the image, and very loud colors (purple, magenta, pink, red, lemon yellow, orange, royal blue, green and other very strong colors) because they completely distract from the attention to the people in the picture.
However, there are plenty of colors that always suit everyone, a jolly joker choice for both young and old: brown and various earth colors, gray, denim, terracotta, rust brown, mustard yellow, burgundy, olive green, khaki green.
Avoid the “uniform” or “dressing together” or “twin” options, because these are already out of fashion, unfortunately… or not unfortunately… but that’s how it is! 😀
Please also avoid clothes with inscriptions or very patterned clothes.