Don't know if you're hand-brushing or airbrushing, but if you're airbrushing, straight Tamiya Clear Blue is a little too strong.
Try cutting it with Clear or Smoke (starting with the clear/smoke and adding the blue) and then thin and airbrush. Experiment a little off the model until you get the efffect you want.
Another option you might consider is Tamiya's Weathering Master set "D", which contains "Burnt Blue" and "Burnt Red" weathering colours. (Tamiya's weathering sets aren't actually powders/pigments. They are more a paste-like hybrid with a waxy carrier.)