The therapeutic palette: how does flower colour influence emotion and behaviour in everyday landscapes?

Urban green infrastructure is recognised as a vital public health resource, yet the specific design attributes that drive its restorative potential remain under-defined. While the efficacy of green vegetation is well-established, the functional influence of floral colour on emotional regulation is often dismissed as purely aesthetic. This research investigates whether flower colour can be used as a precise design tool to support two distinct therapeutic states: relaxation and uplift.
Across four papers, the enquiry progresses from establishing psychological associations to val-idating them in the field and untangling perceptual mechanisms in a controlled virtual environ-ment. Paper I establishes a baseline: cool colours (blues, purples) drive relaxation, while warm colours (oranges, yellows) drive uplift. Paper II interrogates these findings in a real-world set-ting using drone-based behavioural mapping, demonstrating that high contrast and multicol-oured planting significantly extend visitor dwell time and confirming that aesthetic salience translates into behavioural retention.
To isolate the underlying mechanisms, Paper III employs a 360° virtual environment. It reveals a critical "Design Gap": Perceived Colour Diversity—how colourful a scene feels—rather than botanical species count predicts well-being. It also identifies a temporal nuance: cool hues facili-tate stress recovery, while warm hues provide an immediate mood boost without the same buff-ering capacity. Paper IV operationalises these insights by identifying dosage thresholds and demonstrating how warm colours can visually dominate and disrupt a relaxing scheme.
The thesis proposes a framework for "Precision Prescribing" in landscape architecture. Rather than a generic "nature dose," it argues that therapeutic outcomes are modulated by specific visu-al diets. By shifting focus to perceived complexity and tonal precision, the research offers ac-tionable guidance—formalised as Palette Specification Cards—for designers to create environ-ments that actively support their users.