What's the correct PNG format for OS9?

[Syntho]

I've made some custom icons for my hardware synths in Logic. I exported them on my Mac Pro 2008 using both Photoshop and Fireworks but they're not turning out well. When I open them in OS9 it looks like a bunch of weird smearing, like someone dropped some water on a painting or something. I tried PNG 32, PNG 24 and PNG8 and they all look weird.

[IIO]

did you include any custom color palette or color profile? afaik photoshop 5 - 6.5 and quicktime 6 should be able to open all current png files.