[ShiShiLeo]

Gold = Gundam Marker GM04
Silver = Gundam Marker GM05
Black = Gundam Marker GM38

Airbrush is a lot more work. I do not recommend unless you want to repaint the whole model. Markers and paintbrush are better for just details.

For warhammer figure, you have to use a primer (the undercoat which can be any color, but usually grey). That is because you paint those figures with acrylic based paint and that doesn't stick to plastic without the undercoat.

Gundam marker are alcohol based so you can paint directly. This is why I think they are best for details.

Washing does help. Newer model kits are better at being clean right out of the box. Old kits from the 80s and 90s had lots of oil on them. I always wash the runners if I plan to do a full repaint. Oil from your hands also interferes with paint and stickers.