Two coloured arrow

Two coloured arrow

I would like to draw arrows in diagrams that have two colours split along the axis. (This shall represent a mixed case in colour-coded case distinction.) Here's a sketch:
Here is a MWE to play with:
\documentclass{article}

\usepackage{asymptote}

\begin{document}
\begin{asy}
size(10cm);
path p = (0,0)::(1,1){up}::(0,2){down};

draw (p, arrow=Arrow(size=25));
draw (shift((1,0))*p, arrow=Arrow(HookHead, size=25));
\end{asy}
\end{document}
It would be great if the arrow form would match with the default arrows, so they can be used together in a diagram.
I am mainly interested in an Asymptote solution, but if the TikZers and PSTricksers have something to show I am sure this will be appreciated.