What dimm memory has 3 blue slots and 1 black slot?

The DIMM memory configuration with 3 blue slots and 1 black slot is typically associated with a dual-channel memory setup. In this arrangement, the blue slots usually represent one channel, while the black slot represents a different channel or a single memory module. This design allows for optimal performance by enabling dual-channel memory operation with the three blue slots, while still allowing for additional memory capacity with the black slot. However, for best performance, it's advisable to use matching memory modules in the same color slots.