Williams' Muslim faith means that he objects to wearing clothing that markets banks, alcohol and gambling companies.
He taped over a logo for BNZ (Bank of New Zealand) on his Blues kit for last weekend's Super Rugby clash against the Highlanders.
And New Zealand Rugby and the Blues have now agreed to Williams' request that BNZ advertising and a logo for finance company Investec be removed from his kit.
Williams already has a conscientious objection clause in his contract with New Zealand Rugby that means he is not asked to carry out sponsorship commitments with companies involved in finance, gambling, tobacco or finance.
In a statement issued through New Zealand Rugby, reported by several media outlets, Williams said: "I want to be clear that this is nothing personal against the BNZ or Investec.
"My objection to wearing clothing that markets banks, alcohol and gambling companies is central to my religious beliefs, and it is important to me to have been granted this exemption.
"As I learn more, and develop a deeper understanding of my faith, I am no longer comfortable doing things I used to do.
"So while a logo on a jersey might seem like a small thing to some people, it is important to me that I do the right thing with regards to my faith and hope that people respect that.
"I want to thank the Blues and New Zealand Rugby for working with me through this matter over the last couple of days, and respecting my religion and accommodating my request."