The filter differences have now been added to the product description page and are also listed here.

FILTER SOUNDS:

• Black - Maximum attack with powerful impactful bass, rich mids and controlled highs
• Pink - Slightly decreased bass from the black filter with the same mids and highs
• Copper - Maximum bass, lush mids and slightly recessed highs
• Orange - Balanced bass and mids with rolled off highs
• Blue - My personal favourite and beautifully balanced across the range, natural and airy sound with perfect mid and sub bass.