Perhaps this can help:
ParametricPlot3D[{Cos[2 t], Sin[2 t], Cos[t]}, {t, 0, 2 Pi}, PlotRange -> All,
PlotStyle -> Directive[Opacity[0.7], CapForm[None], JoinForm["Miter"], Red],
ColorFunction -> Function[{x, y, z, u}, ColorData["Rainbow"][Sin[x^2 + z - u]]],
Boxed -> False, MaxRecursion -> 0, PlotPoints -> 100, Axes -> None,
Method -> {"TubePoints" -> 30}] /. Line[pts_, rest___] :> Tube[pts, 0.2, rest]
