background C4U cartoon ChIandra4U clouds face fun happy hot illustration kids reflection seascape season sky smile solar spring summer sun sunny vector warm water autumn bavaria birch trees blue sky countryside dry germany grass heath idyllic landscape leafs natural nature November pine trees rural scene spruce sunlight air anchored angles appearance balloon blimp blue cables cameras communication controlled equipment fins floating height high line lines monitor monitoring tethered wired yellow mountain barrier close color colored construction detail fence iron metal paint peak point rustic secure security spike steel strong structure wall bleak cloud colors coloured colours conditions darkness formations light ocean rain shade shadow shapes skies textures variations various cloud formations weather