Found the tool helpful. I'm flirting with the max characters however. The only feature I would request would have it prelimit the gradients to match 255 characters. Instead of cutting characters down to match the gradient, cut the gradient to match the characters. At either rate, i found 11 colors was the maximum. So I'm suggesting take whatever phrase, and merge 2-3 characters to the same color on the gradient.

Thus I was able to make this
-<c val="2c2400">Sl</c><c val="3f350e">ow</c><c val="52461d">ly</c> <c val="65582c">Mi</c><c val="78693b">ch</c><c val="8b7a4a">ae</c><c val="9f8c59">l</c> <c val="b29d68">Ja</c><c val="c5ae77">ck</c><c val="d8c086">so</c><c val="ebd195">n</c>