While some people might disapprove of mourners wearing colours, my friend would say that we should be happy that she’s (hopefully) on her way to Heaven.
While we may mourn our loss, there is a great celebration in Heaven at the coming-home of a soul. We should not forget that.
A friend of Cardinal Basil Hume, upon being told by the Cardinal of his terminal cancer and imminent death, remarked “How wonderful, I wish I was coming with you!”
Death need not be a cause for despair and despond - it can, if we let it be, the opportunity for the celebration of the new birth of a soul into the light of God’s heavenly kingdom as well as a celebration of the life of the deceased. Yes, we’re sad that we no longer have that person with us, but to be too distraught risks an unwise desire to pull that soul back to us when we should be praying that the soul speeds its way into God’s fully realised love.
I do not want black at my funeral. Or dark green, or dark blue, or any other dark colour in predominance. Wear colours. Celebrate my new birth. Celebrate the fact that I finally (hopefully) have the chance to realise the full import of all my sins in Purgatory and can be washed clean of them and my inevitable attachment to them. Celebrate the fact that I welcomed this cleansing and offered myself freely for it. Be happy for my new journey of discovery.