After a little Google search, I couldn't find a canonical answer regarding why Wolverine used to wear those colours. Is it maybe because Wolverine just likes those colours?
I don't know about canonical (as in Wolverine the character choosing the colors), but according to the Wolverine Costume Guide:
Wolverine's original costume introduced his signature blue and yellow color scheme and other apparel that would become hallmarks of the character's look. Featuring blue gloves, trunks, shoulder pads and winged-boots with a red belt over a yellow spandex body suit highlighted with tiger stripes, this would serve as the basis for most of Wolverine's future costumes. Designed by John Romita Sr., the yellow and blue colors were chosen because it presented a new combination in comics.
The beginning of the article starts with: “Ever since his introduction in 1974, Wolverine has changed outfits about as many times as he's killed ninjas—a lot.” However the blue and yellow is his signature look, and is the most commonly recognized Wolverine suit.
For a perhaps in-universe explanation. In some versions of Wolverine's backstory the suit was given to him as part of the Weapon X program. The people in charge decided they liked him in blue and yellow.
According to this site, John Romita Sr. was asked by Len Wein to design a character called Wolverine. Not knowing what a wolverine was, he consulted an encyclopedia, which described the animal as a "catlike carnivore" hence the most likely reason for the catlike costume. In 1980, X-Men penciler and co-plotter John Byrne gave the character a costume with colors more befitting his namesake, but he regained his old yellow-and-blue in 1991 and has worn those colors since, although Wolverine's son, Daken, has worn the brown-and-tan as "Dark Wolverine."
There's also the fact that, well, all of the original X-Men wore blue and yellow. ...Maybe. Or yellow-and-navy, yellow-and-purple, or yellow-and-black; honestly, it seemed like those same costumes changed color depending on who was coloring them. Seriously, here's the cover of X-Men issue #1, from 1963. (Although this image looks like it might be a 1980s reprint.)
Yeah, Wolverine didn't show up until over 10 years later, and by the time he hooked up with the X-Men even the original members had mostly evolved away from those costumes. But, his original costume was pretty much in line with his future team's early look.
Len Wein didn't know what a wolverine was when asked to draw him, so I always assumed he made the costume blue & yellow because those are the University of Michigan (the Wolverines...) team colors.
I was thinking maybe because of University of Michigan Wolverines. U of M colors are Maize Blue and Yellow. That is just my opinion though.