  For integers $k\ge1$ and $m\ge2$, let $g(k,m)$ be the least integer $n\ge1$
such that every graph with chromatic number at least $n$ contains a
$(k+1)$-connected subgraph with chromatic number at least $m$. Refining the
recent result Gir\~ao and Narayanan that $g(k-1,k)\le 7k+1$ for all $k\ge2$, we
prove that $g(k,m)\le \max(m+2k-2,\lceil(3+\frac{1}{16})k\rceil)$ for all
$k\ge1$ and $m\ge2$. This sharpens earlier results of Alon, Kleitman, Saks,
Seymour, and Thomassen, of Chudnovsky, Penev, Scott, and Trotignon, and of
Penev, Thomass\'{e}, and Trotignon.
  Our result implies that $g(k,k+1)\le\lceil(3+\frac{1}{16})k\rceil$ for all
$k\ge1$, making a step closer towards a conjecture of Thomassen from 1983 that
$g(k,k+1)\le 3k+1$, which was originally a result with a false proof and was
the starting point of this research area.
