Loading the xcolor package with the
[table] option provides the command(s)
*) for alternate table row coloring. Any attempt, however, to use
\showrowcolors inside table rows within from LyX -- both in- and outisde a LyX table-float -- results in failing to compile a PDF. The error message is:
Undefined control sequence.
It seems that there is no discussion/question upon this on either LyX-Users' mailing list or tex.stackexchange itself. It certainly is preferable to resolve this in a clean way, i.e. with a correct usage of the above mentioned commands.