This rainbow mantle represent the Joseph anointing. Joseph's father gave him a coat of many colors and shortly after Joseph received it, he began to go through the hardest seasons of his life. His father was not there, but the coat represented his father's covering, support, and belief that Joshep would make it through whatever life threw at him. 
The coat that Joseph's father gave him had many colors because it represented the seasons of life that Joseph would have to travel through in order to obtain his destiny. The different colors were a visual reminder that he was anointed for the different circumstances, test, trials, and seasons that he had to endure on the way to the promise.
Giving this mantle to someone as a gift is a prophetic declaration that they will make it through each season that they have to go through, it is a prophetic sign and symbol that the promise will be reached. It's an honored and cherished event and an occasion to say, I see you, I noticed you, I believe in you and I'm standing with you in faith, prayer and life.
Purchasing this mantle for yourself is visual reminder that you are anointed for whatever is going on in your personal life, your family, and in your ministry. It is a tangible item that reminds you that your trust is in God to cover you, to keep you, to protect you, and to help you accomplish any task at hand. And lastly it's a reminder that all the promises of God concerning you will come to pass in due season if you faint not. 
Philippians 1:6
 He who has begun a good work in you will complete it until the day of Jesus Christ;