It is REALLY bad etiquette to try to stand out from the crowd, unless you are the chief mourner ( or have permission from that person to dress like this).
You should wear a modest outfit - no cleavage, no shorter than just above the knee, no bare legs , nothing sleeveless ( unless you have a black cardigan and never take it off.
No stripper heels.
Colours should be dark - it doesn’t need to be black , charcoal grey, navy, very dark green / maroon / purple / brown are all acceptable.
Nothing patterned, unless it’s a subtle, dark coloured, low contrast pattern.
A White blouse ( or similar ) is acceptable with a dark jacket or coat.
Do not wear a fascinator or veil, if you wish to wear a modest plain hat that’s ok.
Nothing flamboyant, attention seeking or look at me , regardless of the colour. It’s not about you , it’s about showing respect for the deceased and supporting their close family and friends .