So the blocks that're just blue, are blocks found by Ocean as a pool relying on their bitcoin node's template generation. The blocks that show blue and white, are clocks found by miners running their own node as well as running Ocean's DATUM Gateway server, and what that does is allow you construct your own templates yourself, but still pointing your hash to ocean. So it brings back the power to the individual node runner/miner, as stipulated in the white paper.