MiraJane, I prefer the black bunting idea to R.I.P or "DECEASED" and it is a universally understood symbol
Except black bunting or a black stripe or black anything is
not "a universally understood symbol" of mourning. It's is for American, Canadian, Australian, and European culture. But not for other cultures.
Colors for mourning in other countries:
China - white (this is a question on this site.)
Hinduism - white is worn at funerals
India - brown. Widows wear white.
Egypt - yellow
Burma - yellow
Ethiopia - yellow
Korea - blue
Brazil - purple (also a question on this site.)
Thailand - purple
South Africa - red
In 2004, the four daughters of Queen Juliana of the Netherlands all wore white to her funeral.
There were other countries and cultures mentioned that did not use black as a mourning color but I could only find one reference. I never use a "fact" that has only one reference.