bug#55641: Using colours with grep

[goncholden]

Have been using grep to colour the filename printed by tail using grep, by 
setting GREP_COLOR.  However the setting does not work with GREP_COLORS.

Additionally, I could not set colour values with tput commands.

tail -v -n "$tm" $file | GREP_COLOR='01;32' $_GREP -e ^ -e '^==> .* <==$'

awk and sed work better with colour settings, including settings with tput.

Cholden