Latex: change row color of table

An example here:

\usepackage[table]{xcolor}
(if you use pdflatex and/or beamer, perhaps you need to transit 'table' by
\documentclass[xcolor=table..]{beamer} or you will have an error like:
! LaTeX Error: Option clash for package xcolor.
)

\begin{table}
\centering
\rowcolors{2}{gray!10}{}\tiny
\begin{tabular}{c||cc|cc}\hline\hline
....
\end{tabular}
\caption{...}
\end{table}

Latex: Error: ! LaTeX Error: Too many unprocessed floats.

When using too much floating figures or tables, latex fails to locate those elements, you may counter the error:

! LaTeX Error: Too many unprocessed floats.

. One of solutions is to use the package 'float' and add [H] in your figure environment. Example:

\usepackage{float} %before text body

\begin{figure}[H]
\centering
\includegraphics[width=0.8\textwidth]{fig_tauid/plot_compare_tauprop_allvar_TTauAndTauIDTree_20080814_Tau_dalpha.eps}
\caption{Comparison between different samples used in tau ID study.}
\end{figure}