Thwarting internet censors with Collage

What about using covert channels instead of steganography to evade such censorship? I wonder which technique is more vulnerable to detection (both have been well studied in the litterature).

To illustrate the covert channel idea: if a black and white picture is stored, this a "0", if that's a colour picture, then it's a "1".
Of course, practical implementations should try to improve the bandwitdh, possibly with more image types or other types of shared resources: for example (landscape, portrait, fish, animal) mapping to (00,01,10,11).