When you place the flat player bar on the top, the wave bar colors are just automated even though PlayerTopFlat.Wavebar and PlayerTopFlat.Wavebar.Inner are set. If you move the player bar to the bottom, then it respects PlayerFlat.Wavebar and PlayerFlat.Wavebar.Inner. Now move it again to the top, it sometimes follows PlayerTopFlat.Wavebar and PlayerTopFlat.Wavebar.Inner or sometimes shows some weird mixed colors.
In sum, when flat player bar is docked at the bottom, no problem. But on the top, wave bar colors don't work properly.
trying now, the only way i can see this happening is if you dont set all the attributes
<element id="PlayerFlat.Wavebar" fg="19,6,130" fg2="0,170,130" />
<element id="PlayerFlat.Wavebar.Inner" fg="243,14,60" fg2="245,5,25" />
<element id="PlayerTopFlat.Wavebar" fg="193,6,30" fg2="190,130,130" />
<element id="PlayerTopFlat.Wavebar.Inner" fg="3,184,60" fg2="145,145,245" />