On the film's color palette: How does the use of predominantly cool colors (e.g., blue, gray) with occasional warm tones contribute to the overall atmosphere and suggest the characters' states of mind?

1. Overall Color Strategy

The majority of scenes in Infernal Affairs are confined to a cool color palette of blues, grays, and dark teals. Warm colors (the orange of tungsten lights, brown wood, golden sunset hues) are used sparingly as "localized accents" only in key moments. This creates a visual structure where "cold is the norm, warmth is the exception":

• The audience's baseline mood is firmly anchored in the oppressive, alienating, tense cool-toned atmosphere.
• Every appearance of warm color is amplified exponentially, instantly linking to the psychological highs and lows of the characters.

2. How Cool Colors Shape the Overall Atmosphere

In visual psychology, blue and gray lower heart rate and reduce skin blood flow, inducing feelings of "distance" and "rigidity"; the director leverages this physiological response to make the audience share the characters' anxiety and isolation.

3. The Triple Function of Warm Accents

1. Humanity / Belonging:
   • Chan Wing Yan (Tony Leung) and Dr. Lee in the clinic: the warm orange glow of the desk lamp temporarily "warms" the character, hinting he retains a vulnerable emotional core.
2. Desire / Self-Anaesthesia:
   • Lau Kin Ming (Andy Lau)'s living room uses expansive wood tones and warm light; he uses music and red wine to self-hypnotize, a "pretend normalcy" warmth.
3. Flickering Hope:
   • Candlelight in the church, moments of sunset-red rooftops pull good and evil back into the gray zone, giving the audience the illusion that "redemption might be possible."

4. Cool-Warm Juxtaposition & Character Psychology

1. Dual Protagonists Framed Together: Shots often feature a cool background + warm side lighting – visually "pinning" them left/right or front/back, one in shadow, one in light. This represents both their opposing identities and their inner mirroring.
2. Emotional Shifts: Warm colors are swiftly cut back to cool (e.g., rooftop negotiation interrupted by police car blue lights), creating an emotional "drop," pulling the audience away with the characters.
3. Diminishing Warmth: As the plot moves towards downfall, even scenes that should be warm (Lau's home) subtly incorporate teal fill light, symbolizing the gradual loss of the character's self-deceptive "heat."

5. Analysis of Key Scenes

5.1 Opening Deal (Peak Cold)

• Scene: Dock warehouse, overhead fluorescent white light.
• Effect: Characters' skin tones appear bleached, as if "drained of blood," foreshadowing their loss of normal identities.

5.2 Rooftop Confrontation (Mixed Cool-Warm Light)

• Environment: Night-blue city backdrop + warm circle of tungsten overhead light.
• Interpretation: Blue envelops their inescapable fate; the overhead warm light is like a cheap lifebuoy, unable to warm the cold steel beneath their feet.

5.3 Chan Wing Yan's Home (Localized Warmth)

• A warm orange desk lamp and old wooden cabinet compress "home" into a tiny space, while icy teal streetlight seeps through the curtains outside.
• Implication: The character's sense of safety can only "eke out an existence" within enclosed, dim light.

5.4 Lau Kin Ming Listening to Hi-Fi (False Warmth)

• Dim golden spotlights + dark furniture create a surface opulence.
• As the camera slowly pushes in, the background shifts to greenish shadows; warmth clings only around the sound source, symbolizing his inability to be truly "purified" by the music.

5.5 Final Rooftop & Elevator (Cold Closure, Warmth Extinguished)

• Lowest color temperature in the film: Gray-blue sky, unlit metal railings.
• Narrative: The path to redemption is sealed; warmth – the symbol of hope – is utterly absent.

6. Technical Implementation: Achieving Cool-Warm Separation

1. Mixed Light Sources:
   • Interiors: Coexistence of high-color-temperature fluorescent lights and low-color-temperature tungsten lamps allows the cinematographer to arrange cool and warm zones within the same space.
2. Targeted Color Control (DI Grading):
   • Mid-shots retain natural skin tones while backgrounds shift globally towards teal/blue; localized masks are used to boost orange/red where necessary.
3. Art Direction / Costumes:
   • Black, gray, and navy suits form the base palette for male characters; only key accessories (girlfriend's scarf, Dr. Lee's lipstick) provide pops of color.

7. Conclusion

Infernal Affairs accomplishes three things through its "cold as the norm, warmth as the signal" color scheme:

1. Beyond the genre's high-intensity narrative, the cool tones continuously provide underlying psychological pressure.
2. Warm colors act as emotional signals, allowing the audience to instantly recognize a character's current vulnerability, illusion, or hope.
3. Through cool-warm collisions, it metaphorizes dual identities and moral gray areas: everyone searches for a shred of warmth at the edge of freezing, only to be ultimately swallowed by the city's cold light.

As a classic Hong Kong crime thriller, the use of color in Infernal Affairs is a key element in creating the film's atmosphere and hinting at the characters' psychological states. The film masterfully employs a predominantly cool color palette (blues, grays), punctuated by occasional warm tones, constructing a visual world saturated with a sense of fate, oppression, and struggle.

I. Predominant Use of Cool Tones (Blues, Grays): Creating Atmosphere and Hinting at Psychology

The film's overall tone leans towards the somber and heavy, primarily achieved through extensive use of blues, grays, and dark greens. These cool tones not only depict Hong Kong's urban concrete jungle—its towering buildings and dimly lit scenes—but also create a pervasive sense of alienation, oppression, and tension. They symbolize the shackles of fate, the loss of identity, and the moral gray areas, immersing the audience in an intangible pressure and despair.

1. Creating an Oppressive, Fateful Overall Atmosphere:

   • Urban Alienation: Numerous city nightscapes and interior spaces of high-rises (like the police station, apartments) are bathed in cool blues and grays. This palette reinforces the city's cold, mechanical nature and the alienation between people, suggesting the protagonists are trapped within a vast, merciless system with no escape.
   • Tension and Unease: Cool tones inherently carry connotations of calmness, restraint, and even a hint of danger. In key scenes of confrontation, pursuit, or internal conflict, the use of cool tones intensifies the film's tension and unease, keeping the audience in a state of suspense.
   • Moral Ambiguity: The film explores the gray areas between black and white, and cool tones perfectly embody this ambiguity. They represent the absence of clear moral boundaries, only endless confusion and struggle, as if shrouded in a cold mist.

2. Hinting at Character Psychology:

   • Lau Kin Ming (Andy Lau): For Lau Kin Ming, cool tones reflect his internal struggle and gradual descent into breakdown. Trapped in the austere environment of the police station while burdened with the secret of being a mole, this identity dislocation is amplified by the icy blues and grays. His office, apartment, and even scenes with his wife are often bathed in a cold light, hinting at his inner loneliness, anxiety, and inescapable guilt. The cool tones also underscore his ambition and rationality, yet ultimately foreshadow his psychological turmoil and self-destruction.
   • Chan Wing Yan (Tony Leung Chiu-wai): For Chan Wing Yan, cool tones more directly reflect his exhaustion, despair, and yearning for identity. Living long-term in the shadows between the law and the underworld, burdened by lies, the film uses extensive blues and grays to portray the immense pressure and profound loneliness he endures. Whether during rooftop confrontations or sessions with his psychiatrist, cool tones emphasize the coldness and helplessness within him, as well as his faint hope of returning to a normal life. This cool palette also symbolizes his tragic fate—trapped and unable to escape.

II. Supporting Use of Warm Tones: Contrast and Symbolism

Although cool tones dominate, the occasional use of warm tones in the film serves a crucial contrasting and accenting role. They often signify fleeting hope, dangerous temptation, false warmth, or fading memories.

1. Fleeting Hope and Redemption:

   • For example, scenes where Chan Wing Yan interacts with his psychiatrist, Dr. Lee Sum Yee (Kelly Chen), sometimes feature faint warm light. This symbolizes his deep-seated longing for redemption and understanding, offering moments of brief tranquility. However, this warmth is often fragile and transient, ultimately swallowed by the cool-toned reality, emphasizing the elusiveness of hope.
   • In some flashbacks, particularly those involving Chan Wing Yan's past with his girlfriend, slightly warmer tones might appear, but often filtered through a layer of nostalgia or sadness, highlighting the irretrievable nature of happier times and the regret of loss.

2. Dangerous Temptation and False Warmth:

   • Conversely, scenes in Hon Sam's (Eric Tsang) office or other triad settings might feature dim red or orange-yellow lighting. This does not represent genuine warmth but rather hints at the bloodiness of power, dangerous temptations, and the false camaraderie within the triad. This distorted warmth contrasts sharply with the cool tones, further highlighting the complexity and danger of the underworld. It might represent a superficial sense of "home," but its essence is decay and violence.

III. Interweaving and Interaction of Cool and Warm Tones

The color aesthetics of Infernal Affairs lie in the skillful interweaving of cool and warm palettes. Cool tones establish the oppressive and fateful foundation, while the occasional flash of warmth acts like a glimmer of hope in despair or a warning of danger. This contrast not only enriches the film's visual lexicon but also profoundly serves its themes of identity, choice, fate, and redemption. Cool tones represent the harshness of reality; warm tones represent inner longing or superficial disguise. Together, they construct Infernal Affairs' unique and unforgettable visual style, precisely conveying the protagonists' infernal struggle and tragic destiny.