doors escape exit fire door keep clear no obstruction safety security warning caution close communicating communication door fire fire-door information informing keep-clear keep-closed no-obstruction red risk risks risky wording words architecture building extinguisher fire extinguisher hotel house lamp Nyberg staircase stairs black circle knob old open porto Portugal sun brigade chimney gate home huge ladek Poland roof sky sole tile wall yellow zdroj anonymous blank blue danger estate factory fence industrial industry ladder metal modern perspective railings stair unit window arrow dangerous directing direction directions doorway emergency emergency exit exiting green guide help icon indoor instruction leaving life man path protection run running save sign signs symbol urgency angles appearances architectural architectural elements Colonial colors colours contrast contrasting distinctive elements exterior external fire station glass high linear lines patterns perspectives Singapore style sunlight tall textures views walls windows wooden