Hi Chris,
For knots you can use KnotData. e.g. for an interactive 3D image
KnotData[{"TorusKnot", {3, 5}}, "Image"]
One way to customize the appearance is to get the functional form and plot it
f = KnotData[{"TorusKnot", {3, 5}}, "SpaceCurve"];
ParametricPlot3D[f[t], {t, 0, 2 Pi},
ViewPoint -> {Pi/2, Pi/2, 2},
Axes -> False,
Boxed -> False,
ColorFunction -> "Rainbow",
PlotRange -> All] /. Line[pts_, rest___] :> Tube[pts, 0.2, rest]
Not sure how to add an interactive version to your website. Maybe you can use one of the supported 3D export formats.