How to put white line separator for cell/column?

How can I separate columns and cells with white lines. I googled and found we can put \hline and | in table definition but that produces black line.

 \documentclass{article}
\usepackage{array,multirow}
\begin{document}
\begin{tabular}{|c|cc|}\hline
\multirow{4}{*}{Foo} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\multirow{4}{*}{Bar} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\end{tabular}
\end{document}


How can I change them to white line?

-
Sorry I didn't understand. White line in white backgroud? Simply don't use | and \hline. If you are using colors for cells/rows/columns, then you can color them using colortbl package. – Harish Kumar Jan 16 '13 at 4:42
I have deleted the biblatex tag since nowhere in your problem did I see something related to it :) – hpesoj626 Jan 16 '13 at 4:43
My background is blue actually. – manish Jan 16 '13 at 4:43
Yes, blue background. – manish Jan 16 '13 at 4:45

Use colortbl. I have used blue just to demonstrate as here background is white. You may change blue to white (\arrayrulecolor{white}) in your actual case.

 \documentclass{article}
\usepackage{array,multirow,colortbl}
\begin{document}
\arrayrulecolor{blue}         %% change blue to white in your case
\begin{tabular}{|c|cc|}\hline
\multirow{4}{*}{Foo} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\multirow{4}{*}{Bar} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\end{tabular}
\end{document}


For details Refer to documentation of colortble page 5 and 6 sections 7 and 8. To get documentation run texdoc colortbl from command prompt or visit texdoc.net

Another option is to use xcolor package with [table] option:

\documentclass{article}
\usepackage{array,multirow}
\usepackage[table]{xcolor}
\begin{document}
\pagecolor{blue!40} %% just to demonstrate - remove in your file
\arrayrulecolor{white}
\begin{tabular}{|c|cc|}\hline
\multirow{4}{*}{Foo} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\multirow{4}{*}{Bar} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\end{tabular}
\end{document}


Edit:

It works for long tables also:

\documentclass{article}
\usepackage{array,multirow,longtable}
% \usepackage{colortbl}
\usepackage[table]{xcolor}
\usepackage[textheight=10cm]{geometry} %% onlly for testing
\begin{document}
\pagecolor{blue} %% just to demonstrate - remove in your file
\arrayrulecolor{white}
\begin{tabular}{|c|cc|}\hline
\multirow{4}{*}{Foo} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\multirow{4}{*}{Bar} & 1 & 2 \\
& 1 & 2 \\\cline{2-3}
& 1 & 2 \\
& 1 & 2 \\\hline
\end{tabular}

\begin{longtable}{|>{\bf\centering\arraybackslash}p{1in}| p{2in}|}
\hline
\large{Name} & \large{\textbf{Definition}}\\ \hline
\hline
\large{Name} & \large{\textbf{Definition}}\\ \hline
\hline
\multicolumn{2}{r}{continued \ldots}
\endfoot
\hline
\endlastfoot

Newton's first law & An object will \\ \hline
Newton's second law & The net force \\\hline
Newton's third law & When two bodies \\ \hline
Linear momentum & The product of an object's \\ \hline
Net force on a body & Is said to be equal \\ \hline
Impulse of a force & The product of \\\hline
Principle of conservation of momentum & In a closed system, \\
\hline
Perfectly elastic collision & A collision is \\ \hline
Inelastic collision & A collision is \\ \hline
Radian & $\pi$ radians = $180^\circ$\\ \hline
Gravitational field strength & The gravitational force
\\\hline
Newton's law of gravitation & Any two point masses\\\hline
\end{longtable}
\end{document}


Edit:

For a query in the comment below:

You may use some thing like

\newcolumntype{M}[1]{>{\centering\arraybackslash}p{#1}} %% this needs array package
\begin{longtable}{|M{1.4cm}|M{1cm}|M{1cm}|M{3.7cm}|M{1.8cm}|M{1.8cm}|}

-
I am using longtable and still same pblm persists. How can i fix this? – manish Jan 16 '13 at 6:30
@user15662 See the edit. – Harish Kumar Jan 16 '13 at 6:55
My longtable definition: cat("\\begin{longtable}{ >{\\rule{0pt}{.5cm}} >{\\centering\\arraybackslash}p{1.4cm} >{\\centering\\arraybackslash}p{1cm}>{\\centering\\arraybackslash}p{1cm}>{\\centering‌​\\arraybackslash}p{3.7cm}>{\\centering\\arraybackslash}p{1.8cm}>{\\centering\\arraybac‌​kslash}p{1.8cm}}","\n") , How can i put vertical bar inside it. – manish Jan 16 '13 at 7:19
Great answer! Thankyou very much. – manish Jan 16 '13 at 7:46