Hi OK,
A violin is really much like any other outfit - the more you pay the better you should get but be carefull.
1. Try to make sure that your violin has been set up by a proffesional violin specialist. Many of the shops which do general music supplies do not always as a rule have a specialist on hand to do this so if you can find a maker who sells new instruments then your sorted.
2.Thecoloured violins are basically the cheaper end of the starter kits given a shiny finish. The quazlity with these instrumentes will vary as does the wind.
3. If at all possible try the instrument in the shop before you buy and ask the shop if the instrument has been set up and by whom.
4. Remember if you are in your first years of playing then you really do not need a very very expensive violin but something you can learn the tricks of the trade on.
GOOD LUCK