Don’t know if this is significant, but it was the top search result on google when searching ’wearing blue at a funeral’:
Generally speaking, black is still the proper attire for funeral clothing. However, if you are not related to the deceased, you can wear navy blue or dark grey as well. It is not necessary to go out and buy a black suit or dress if you don't already have one.
Don’t know if this is significant, but it was the top search result on google when searching ’wearing blue at a funeral’:
https://andersonfuneralservices.com/blogs/blog-entries/1/Articles/16/Modern-Day-Etiquette-Tips-for-Funeral-Clothing.html
Also this about the significance of the color blue:
https://www.thekewlshop.com/blogs/news/14-things-the-colors-you-wear-say-about-you