CBB dye interact with protein through ionic and vandarwaals interaction. SDS (detergent) thus interfere with these interactions leading to pale blue protein bands with higher background. So, before staining, it is necessary to wash the gel with distilled water for 3-5 min.

Thanks Amaj. But do you have any suggestions for me to rescue my gel staining, since I've completed staining and destaining..

If SDS merely compete with CBB, do you think I can just destain completely, then boil my gels in water to remove SDS and then go for another run of staining?

Yes, I think this may help you to get a better band.