The background is purple/blue, and light gray/purple/light blue bridesmaid dresses are ok.
The background is pink/white/champagne, and bridesmaid dresses with red bean paste/light pink/champagne can be used.
If the bride's toast dress is pink/meaty powder, then the bridesmaid can wear champagne/light gray, which is lower-key than the bride's color.
If the bride's toast dress is big red/burgundy, then the bridesmaid's dress only needs to match the wedding background color.
Bridesmaids had better not wear dark dresses such as white and red/burgundy/black/royal blue/navy blue.
PS, the above is purely a personal opinion, just refer to it. Attached are some color pictures for your reference. Just refer to the color. There are many styles on the internet, so you can search a lot. The main thing is not to be too eye-catching and beautiful.