Raydians who are captured by Inkies are turned into slaves called Graydians. They are then forced to do all sorts of horrible jobs for the Inkies from randomly pressing buttons, pulling sledges through the snow, doing maintenance work, and even creating new Inky soldiers.
They are forced to wear large, round grey suits, which makes the trapped Raydian inside miserable. The suit has a black tear drop-shaped symbol on the top and four holes in the back of it. It is possible these suits are very heavy to wear, as some Graydians are seen struggling to walk in them and some even roll around to get around. Furthermore, while Raydians come in all sorts of shapes and sizes, Graydian suits are all exactly the same.
The worst possible thing about being turned into a Graydian is that the suit converts their misery into a pure ink substance. Once the suit is full of ink, the Inkies then harvest the ink out the Graydian. They do this by attaching the Graydians to a machine which spins them around and drains the ink out through the holes in the back of the suit. The ink is then pumped into vats. In de Blob, the machine the Inkies use to harvest the ink is a converted funfair ride, but they probably have other similar machines in other places.
In order for Blob to get more time in a level and earn the Liberation award at the end of each level he must rescue all of the Graydians in the level. Some can be found out in the open usually on top of certain platforms, but most are trapped inside buildings. To free them, Blob must paint sets of buildings. Once Blob has successfully painted a set of buildings a message will appear to say the Graydians have been freed and they will rush out of a building into the open area, usually in groups.
Whilst coloured, Blob can roll over a Graydian which then cracks open their suit and releases the trapped Raydian inside. If Blob rescues an entire group of Graydians he is then awarded with a time bonus. This is usually (if not always) an additional 60 seconds with which to complete the level. This is a larger time bonus than the 30 seconds awarded for returning a group of Blancs back to their Raydian selves. This makes sense, as the Blancs are technically enemy characters, and defeating clusters of enemies in the De Blob games always grants an additional 30 seconds.