  This is the second part of three episodes to demonstrate a renewal approach
for proving the Four Color Theorem without checking by a computer. The first
and the third episodes have subtitles: ``RGB-tilings on maximal planar graphs''
and ``Diamond routes, canal lines and $\Sigma$-adjustments,'' where R/G/B stand
for red, green and blue colors to paint on edges and an MPG stands for a
maximal planar graph. We focus on an extremum non-4-colorable MPG $EP$ in the
whole paper. In this second part, we refresh the false proof on $EP$ by Kempe
for the Four Color Theorem. And then using single color tilings or RGB-tilings
on $EP$, we offer a renewal point of view through R/G/B Kempe chains to enhance
our coloring skill, either in vertex-colorings or in edge-colorings. We
discover many fundamental theorems associated with R-/RGB-tilings and
4-colorability; an adventure study on One Piece, which is either an MPG or an
$n$-semi-MPG; many if-and-only-if statements for $EP-\{e\}$ by using Type A or
Type B $e$-diamond and Kempe chains. This work started on May 31, 2018 and was
first announced by the author~\cite{Liu2020} on Jan.\ 22, 2020, when the
pandemic just occurred.
