not quite martians, these little fellas are bollards you'll find on Damrak in Amsterdam.
They line the busy side of the road to the right as you leave Centraal Station toward Dam Square.
Quite a lot of Photoshopping one on here, basically made 2 layers, made one Blue wthe the Hue/Saturation control then blended them with a wierd blend mode - I forget which - till I got an alien effect.
Similar processing to the above, though used the Select Colour... control to grab the midtones only. Then changed one layer to a Cyan colour, you'll notice that the transition frmo mid-high and mid-low tones has an almost metallic effect as a result.