When it comes to whether your car comes safely through the coming winter (frost) period, you can have the freezing point of the coolant checked at a garage or at an old-fashioned gas pump. You can also do it yourself by buying a tester for a few euros at the Halfords etc. This is a kind of tube with a number of different colored balls in it, with a rubber bellow on one side and a tube on the other. Insert the tube into the coolant of your car and draw it into the tube. Watch which balls float and which sink. The color of the lower ball that still wants to float indicates the degree to which the liquid protects against frost. This is usually indicated on the side of the tube. If necessary, have the dealer replenish antifreeze. Prefer not to mix or add coolants with water. With the old 'antifreeze' it worked, With the current coolants it can reduce the anti-cavitation and lubricating effect.
But for the less critical minds, the Action regularly sells coolant for something from 2 euros per liter or less.
Oh yes: coolant can have just about every possible color. That is not quality related.