They don't give a shiny shite what you're wearing. So long as you look smart, which you would...
With respect, and I mean that and am not trying to start a bunfight on a sensitive thread, you are wrong IMO.
Funerals are as much about the living as the dead. They aren't here. They cannot see and are beyond hurt.
As I said, I thought I was doing the right thing by wearing my smartest coat to my dad's funeral. My mum, who also took pride in her appearance, was offended by the colour, which wasn't as bright as the top OP is thinking of wearing, but was bright.
I was surprised at her angry reaction. She never shouted at me at other times but grief does terrible things to people. He was my dad, and I was grieving too, but he was her soulmate and what she wanted was more important.
Luckily it was sorted out before I turned up in it. I wore a parka - not my choice of coat for a formal occasion at all. But it was winter and I needed a coat and she was happy because it was dark blue.