Top of her agenda is turning her focus to pay parity, building up gender balance at leadership level and boosting ethnic representation in leadership.
She'll also be rounding out the work to gain the Rainbow Tick accreditation and looking at ways that Spark, particularly its big business arm Spark Digital, can engage with the growing Maori economy.
Taking the lead on diversity at Spark has been a career shift for Koroheke, who has affiliations to Ngapuhi, Ngati Maniapoto and Te Whanau-a-Apanui.
She started with the company back when it was still the Post Office and she was looking to earn enough to go on her OE.
Returning home in the 1990s, she re-joined what was then the state-owned enterprise Telecom - originally on a three week contract in the technology side of the business.
That short-term contract became permanent and over the next 20-plus years she worked in large technology teams at Telecom and its IT contractor EDS, at times leading up to 150 people.
Working in the technology side of the business, with its fast pace and shifting directions, helped her develop resilience and the ability to bring others along on the transformation journey, she says.
Koroheke, who is now Spark's most senior Maori leader, says at no stage did she feel that being a Maori woman made her any different to those around her.
She credits supportive managers for ensuring she had opportunities to rise through the ranks.
"I did not feel at any time that there was any discrimination, I just did not feel that, although I'm very acutely aware that it existed but I didn't see that stopping me achieving what I have achieved."
She says Theresa Gattung's appointment as Telecom CEO in 1999 was a watershed moment. "That was, in itself, a huge feat and that gave me more inspiration that one day I could move up to senior realms of leadership - it was proven that it could be done."
Another game changer came in 2015, on a year-long leadership course run by Global Women. Mixing with women in senior leadership roles and hearing how they operated in other organisations was eye opening, she says.
But it was a talk by Dame Jenny Shipley that really challenged her.
Shipley described a line in the sand that you can either walk up to or cross over into another world of understanding leadership, governance and success. She asked the women to think about what they had achieved to date and what more they could do, Koroheke says.
"That really resonated with me."
Shipley also told the women no one was going to come along and offer it all to them. "If you want it you need to go out and get it," says Koroheke, quoting Shipley.
"Having been in technology for as long as I had and seen a lot of changes going on I actually felt, you know what, I need a change, I need to open up a pathway for another emerging talent coming through the ranks to step into my shoes and take over from where I was leaving.
"I want to go off and do something else."
Koroheke says she wanted to focus on helping others be the best they could rather than driving projects aimed at achieving company deliverables, and was happy to leave Spark to head in this new direction.
But when Spark started talking about its diversity and inclusion ambitions early last year, Koroheke realised her dream job was right under her nose.
In the eight months since she took on the role she has had the support of Spark boss Simon Moutter, but also some mentoring from BNZ's Anthony Healy, who she says has given her some fantastic advice.
And while there has been a mountain of work to get through, Koroheke says she hasn't encountered any resistance from the business.
She had thought the drive to get the Rainbow Tick would be challenging but it wasn't.
"That said to me: right we're open to anything.
"I know that this isn't always going to be a walk in the park and I am ready for the doubters or those that think we're on the wrong path.
"I'm absolutely ready to challenge and understand where they're coming from and to help influence their way of thinking because it's all about changing mindsets and awareness."
