abstract backdrop backgound canvas colors colour colours grubby grunge grungy hues messy paint series shades spatter texture tones variation variations aged alert area background blank bolt bolts brown copy fence icon industry inform information isolated metal old painted placard plank planks plaque retro risk rust rusty sign space square steel triangle wall weathered white wood wooden yellow art blot blotch blotches clip art clipart graffiti graphic illustration ink liquid red splats splatter stain blue black alarm danger dangerous death electric electrical electricity green hazard notice peeling warning color distorted distortion pastel rough wave waves wavy