1. A graphics system comprising: a memory device, wherein the memory device comprises a level-one cache, a level-two cache and a random access memory (RAM) storage; a data request processor configured (a) to receive a read clear request comprising a source address corresponding to a RAM block in the RAM storage, (b) to control a transfer of data from a first level-one cache block in the level-one cache to an output buffer, wherein said data in the first level-one cache block is a copy of identical data in the RAM block of the RAM storage and identical data in the level-two cache, (c) to set one or more bits in a first dirty tag associated with the first level-one cache block, and (d) to set a first mode indicator associated with the first dirty tag to a read clear mode; a block cleansing unit configured to examine the first dirty tag associated with the first level-one cache block, and to issue a color fill command to invoke a color fill transfer operation from a color fill block in the level-one cache to the level-two cache in response to detecting that said one or more bits of the first dirty tag are set and that the first mode indicator is set to the read clear mode; wherein said data from the first level-one cache block is usable to generate a displayable image.