the command to change the colour is color bf (where b is the background and f is the foreground, the link I supplied will give more information on that
color 40 will give a red background with black text
color 0f is to change it back to black background with white text.
colour 40 change colours
echo Warning add warning lines
set /P c=Do you want to continue[Y/N]? prompt (wait for response)
colour 0f change colour back
if /I "%c%" NEQ "Y" Exit deal with the response from user