fix typo(?) in colortimelines using color.r instead of slot.r when using alpha

spine-lua/Animation.lua

@@ -372,7 +372,7 @@ function Animation.ColorTimeline.new ()
 		local b = lastFrameB + (frames[frameIndex + FRAME_B] - lastFrameB) * percent
 		local a = lastFrameA + (frames[frameIndex + FRAME_A] - lastFrameA) * percent
 		if alpha < 1 then
-			slot:setColor(slot.r + (r - color.r) * alpha, slot.g + (g - color.g) * alpha, slot.b + (b - color.b) * alpha, slot.a + (a - color.a) * alpha)
+			slot:setColor(slot.r + (r - slot.r) * alpha, slot.g + (g - slot.g) * alpha, slot.b + (b - slot.b) * alpha, slot.a + (a - slot.a) * alpha)
 		else
 			slot:setColor(r, g, b, a)
 		end