Some timeline things since after years (decades) it all blurs together and assumptions and errors start getting repeated as facts:
Maeve began a leave of absence from GL in August 1996 during the Laibson/McTavish horror show, supposedly to get herself out of the shit fest Wendy Moniz was flinging backstage. During her LOA that executive team was fired and replaced with the unholy triumvirate of Rauch/Esensten/Brown. He came in during her absence, she didn't leave because he was there. But, It WAS feared that Maeve would not return to the show with Rauch in charge, due to their history, but he swore he had changed and both parties thought the ugliness of years prior to be water under the bridge.
So, she returned to the show in May 1997 and got about 6 months of (not-great) story before she and Kurt McKinney (he played Matt) were sidelined for the emerging all Reva all the time hour, which began in September 1997, first with stripper Cassie's arrival followed by the clone that spring 1998. Maeve got minimal airtime doing and saying stupid shit, mainly in the way of taking constant abuse from Dinah about her miserable childhood.
When the Vanessa/Matt/Beth triangle played there were daily 'you're a hag get a facelift' comments from other characters, including talking to a plastic surgeon about fixing her sagging face, meanwhile Kim Zimmer looked like she'd spent the winter moonlighting as a sandbag and got lines about how Reva struck men down with her beauty. As a viewer, it was hard to feel like this stuff wasn't the result of some personal backstage crap.
It was for the second (third?) Josh/Reva wedding in 1999 that Vanessa showed up to the ceremony with blonde hair. As someone said it was during the Rauch blonde fetish years where everyone had platinum hair, wore neon-colored airline hostess suits, and had their tits out on display. Maeve herself has said she campaigned heavily during this time to go gray, but the producer (Rauch) wouldn't let her, until she finally wore him down.
She only got her way when she went off-contract and was coming in to film on recurring status. The story at the time was Vanessa's slow death from lip balm, where the character of Vanessa goes into a coma and lies in bed for 5 months. When Vanessa wakes up and realizes she'd shot Ben Warren, an all-gray Vanessa ends up confronting Carmen.
Maeve ultimately left the show a few months later in July 2000, when she walked off the set with no notice (none was required - she was recurring) after filming the Bauer BBQ.