Merlin and Hermes: Mysterious Lines

Two adventurers, Merlin and Hermes, approached a large iron door built into a cliff face."Well...", said Hermes, "What do we do now?". Merlin produced an old, large piece of crumpled paper from his pocket. "Hrm...", Merlin mumbled. "It says here that we must speak the six letter keyword to open the door and enter the secret chamber, but I don't remember seeing any signs as to what that keyword might be..."

After a bit of searching, Hermes notices something etched into the ground. "Come over here!", he yelled, pointing frantically. And sure enough, barely visible and obscured by dust, was a series of lines of differing color etched into the ground:

"Ah", Merlin said, "So that is the keyword." Hermes was lost and confused. After staring at it for another thirty seconds, he grumbled "What keyword!? All I see is a bunch of lines!". Merlin simply responded, "You're just looking at it the wrong way. It's obvious!"

Isn't it?


The signs are engraved letters on the ground and Merlin and Hermes are looking at them from above (the italic "looking at it the wrong way" is a hint). The darker a part from some sign is, the farther from the ground it is. The only letters which could correspond to this description are U - N - L - I - N - K. Therefore the keyword is "UNLINK".