It will take place next week at Lichfield Cathedral in Staffordshire.
In a statement, her family said there were no rules on what to wear at the service next Tuesday.
Ms Saward, 51, died after a stroke last week.
She was the first rape victim to waive her anonymity after she was attacked at her father's vicarage in Ealing, west London, in 1986.
The statement read: "If you are mourning and grieving, and want to wear black or dark clothes; do so. If you want to celebrate her life and all that she was, and want to wear bright clothes; do so.
"If you want to make a statement against sexual violence, and want to wear purple; do so. If you want to celebrate the life everlasting with God through Christ that Jill is now experiencing, and want to wear white; do so. Just come as you are and as you feel comfortable."
Meanwhile, people who wish to make donations in memory of Jill are invited to offer their support to the Cambrian Coast Evangelical Trust, Ehlers-Danlos Support UK or the Merseyside-based Rape and Sexual Abuse Centre.
Collection boxes for the three charities will be available at the cathedral for those attending the funeral.
