Between a long-sleeved white shirt and a long-sleeved black shirt (Mandarin collar), which looks more appropriate for a funeral?

I have to go to a funeral today, and I don't plan on wearing a suit or a jacket.
I'm planning to wear black slacks with a long-sleeved shirt.
However,
the black shirt (not pitch black, more like navy) has a Mandarin collar, while the white shirt has a regular collar.
Which one would look more decent?
Gemini recommends white, while GPT recommends black.
I do have a suit, but the reason I'm not wearing it is partly due to the weather, but also because
I have to travel to another region via public transportation,
and the biggest problem is that the heel of my dress shoes happened to wear out and broke.
The only shoes I have to wear are white sneakers, so I thought dressing like this would be better than wearing a suit with them.
The sneakers are also weighing on my mind, but given the current situation, I have no choice.