Hi mate
For the blue, it depends on what kind of look you want from it?
The Werkstatt Acrylic would still look great on that particular colour, giving a very reflective look with mega flake pop, but the depth of shine wont be as deep as some other products can produce:
If it were my car then i would go for Blackfire Wet Diamond, which again is a sealant but this produces a very wet, reflective and glossy look to the paint. Plus if you want even more wetness and depth you can top it with Blackfire Midnight Sun wax which has been designed specifically to work on top of the wet diamond and this will boost durability too.
This is a link to scoobynet where a customer posted pics of his car after using the Blackfire products:
http://bbs.scoobynet.com/car-care-380/6 ... bliss.html
The Blackfire is by far the easiest products to use and if you need any more pics for examples then just give me a shout as i'm sure there's some kicking about on the computer somewhere
As for knowing which Werkstatt Sealant to use:
For solid colours such as red for example, then use the carnauba range, as this will give a warm deep glow to the paint which suits solids better.
Use the Acrylic on metalic paints and light colours such as white/silver/Ice blue etc
On dark grey, either the Blackfire or Werkstatt Acrylic would look good so its a personal preference really in what kind of look you want to go for. Wet and glossy (Blackfire) or Sharp and reflective with great flake pop (Werkstatt Acrylic).
Hope that helps, any more questions feel free to ask
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