en General Architecture General Architecture Research Paper Research Paper <i><span lang="EN-AU" style="font-size:11.0pt"><span style="font-family:&quot;Times New Roman&quot;,&quot;serif&quot;">The visual atmosphere of hospitality interiors plays a significant role in attracting customers and shaping their perception of space, yet its links to emotional response and time perception remain underexamined within interior architecture research. Addressing this gap, this study examines lighting and colour in restaurant interiors as a representative hospitality setting in which atmospheric variations can substantially influence customer behaviour. Adopting a multidisciplinary quantitative approach that integrates indoor environmental quality (IEQ), marketing, and behavioural psychology, the research tested four hypotheses using data collected from 441 participants in Tehran. A comparative analysis was conducted across four lighting&ndash;colour conditions of restaurants: warm/bright, cold/bright, warm/dim, and cold/dim. The findings demonstrate that lighting and colour significantly influence both emotional response and perceived waiting time, although in contrasting ways. The cold/bright condition generated the strongest emotional response, whereas the warm/bright condition was most effective in reducing perceived waiting time. Both variables significantly contributed to customer attraction, with emotion showing the stronger predictive effect (&beta; = 0.520 compared to 0.346). The findings redefine IEQ, focusing on light and colour, as an active and measurable design strategy rather than a passive decorative background.</span></span></i> Indoor environment quality, Light and colour, Restaurant environment, Emotion, Perception of time 0 0 http://ijaup.iust.ac.ir/browse.php?a_code=A-11-2036-1&slc_lang=en&sid=1 Ali Shirazinejad alishirazinejad@ut.ac.ir 180031947532846008576 180031947532846008576 No Faculty of Management, University of Tehran, Tehran, Iran Erfan Heidari erfanh941@gmail.com 180031947532846008577 180031947532846008577 Yes University of Melbourne, Australia Mohammad Rahim Esfidani esfidani@ut.ac.ir 180031947532846008578 180031947532846008578 No Faculty of Management, University of Tehran, Tehran, Iran