LEGO part 3710 - Trans-Dark Blue Plate 1 x 4 at BrickScout
LEGO Part Dark Blue Plate 2 x 4 - Brick Land
2x6 Plate, Lego® Part Number 3795 Trans-Light Blue – Atlanta Brick Co
Amazon.com: Classic Blue Plates Bulk, Blue Plate 1x2, Building Plates Flat 100 Piece, Compatible with Lego Parts and Pieces: 1x2 Blue Plates(Color: Blue) : Tools & Home Improvement