If I'm understanding you correctly, you want to change the palettes used in the Bowser battle. You cannot do this via Lunar Magic directly as Bowser & his Clown Car have hardcoded colours defined by ASM.
Also, he uses palette 'E', not palette '0'
However, if you can work with only 7 colours, there is a tool called Iggy/Larry Battle Tools
that will allow you to change the hardcoded colours found in Bowser's Battle.
To answer your direct question; if there is a way to use all the colours in a palette row for Bowser, I would assume it's possible, but I do not know how. The tool above is a good start, but perhaps someone more knowledgeable will know if the rest of the row can be used.