Hey mate, they're all gone sorry.  You'd be much better off with a pH meter though.  It's pretty hard to tell the difference between colours and they're not great value for money IMO.  A pack of these worked out at about $20 each and you can pick up pH meters as low as $30 - http://www.trademe.co.nz/business-farming-industry/industrial/measu... Hope that helps mate, cheers.

Thanks man.... Ill take a look at the meters

 

cheers