Does not arrows style or color option apply an arc in \xymatrix? Please let me know the way.
\documentclass{article}
\usepackage[arrow, matrix]{xy}
\begin{document}
\[
\xymatrix{
A \ar@{.>} `d[r] `r[dr] [dr]& \\ & B
}
\]
\end{document}

\xymatrixhelpor Commutative diagram with curved arrows, colour, and changing the style of arrows you?tikz-cdpackage instead. It is almost the same syntax, the arrow macros are named differently. Plus the bonus of all thetikztricks