A method for selectively compressing unstructured data includes preparing, at a host system, a data blob made up of unstructured data, for storage on a storage system. The method encodes a first portion of the data blob with a first color and a second portion of the data blob with a second color. The first color indicates that the associated portion should remain uncompressed, while the second color indicates that the associated portion should be compressed. The method transmits the encoded data blob to a storage virtualization layer associated with the storage system. In response, the storage virtualization layer stores the first portion in an uncompressed format, and compresses the second portion and stores the second portion in a compressed format. A corresponding system and computer program product are also disclosed herein.