It's not a solution to anything. Will changing the color suddenly not make it racist in the eyes of those who think Zwarte Piet is racist? No. You still have 'servants' working for a older, wiser white man, 'servants' that used to be black.
Okay, clearly you don't really know the origins of Zwarte Piet and Sinterklaas. Let me give a recap for the people that don't know either:
The Sinterklaas festival has been around for way, way longer than colonialism and even Zwarte Piet. Sinterklaas was based on a Turkish (back in the days of the Eastern Roman Empire) holy man called Nicolaas of Myra. He was the patron saint of kids and that's where Sinterklaas as a festival for kids comes from. Originally he was meant as a boogieman for naughty kids, but over the years he transformed into a kind man.
Zwarte Piet was introduced in the late 19th century (after the colonialism era) by a picture book called 'Sinterklaas en zijn Knecht'. This knecht (page) was clearly racist in tone, as many people were those days (even renowned writers as H.P. Lovecraft and Edgar Allen Poe were extremely racist). The (unnamed) page in this book was some sort of boogieman, scaring naughty kids while Sinterklaas gave the nice kids candy and toys. It's interesting to note that the first 'Piet' (who wasn't called that yet), was on his own. Occassionally there would be two, but never more.
The idea of multiple Pieten at the Sinterklaas festival actually didn't come from the Dutch, but from the Canadians, who all dressed up as Pieten after the Second World War. Throughout the years the image of the Pieten has changed. Up until the mid-80's you could argue that the original ('racist') origins of Zwarte Piet were still there, he was still the boogieman who would take you away if you had behaved badly. In the late 80's/early 90's this changed though (just like that happened centuries before with Sinterklaas) and Zwarte Piet became a kind helper that entertained the children with jokes, acrobatic tricks, fun adventures (De Club van Sinterklaas, a show every child watches, is all about how the Pieten singlehandidly save the Sinterklaas festival every year from cartoonesque bad people who try to stop Sinterklaas).
Also, as many people have pointed out, for the past ten years they have seperated themselves from the racist stereotype even more by no longer using red lipstick en masse (only certain Pieten still had it). The only thing that stayed was the black color, simply because the Pieten are called Zwarte Pieten and the black color is just part of their attire.
Anyway, the point is that while De Zwarte Pieten may have started as a racist stereotype heavily influenced by the colonial age
(but by no means did it start in the colonial age), they haven't had a racist or scary connotation in years. We, as kids, just have fun with it and see these Pieten as fun, kind people who give us candy, presents and have these grand adventures to protect the festival. Furthermore, in the 90's one of the most popular children's music bands in the country (VOF de Kunst) made a song celebrating the black Zwarte Pieten in the song
Witte Zwarte Pieten (White Black Petes) in which they state that the white Zwarte Pieten are nasty people who are basically the boogiemen that the Zwarte Piet started as and that that's why Sinterklaas doesn't take them with him.