A person's emotions are typically read by changes in their facial expression and tone of voice, but some characters and creatures go further, and may experience dramatic physical changes in response to their shifting moods.
This often takes the form of changing colors, such as in the tone of a person's skin or in glowing effects. In these cases, this goes hand-in-hand with Color-Coded Emotions, causing characters to literally become red when angry, blue when sad, and so on. Other changes may be more physical in nature; an angry character may grow spikes or claws, for instance, while a calm one may soften into a blob-like shape.
This may cause complications for these characters, as it will make it effectively impossible for them to hide or disguise their feelings or reactions. Physical changes may prove more useful as responses to the causes of the emotion, such as by giving an angry character natural weapons or making a frightened one more able to hide.
This often overlaps with Involuntary Shapeshifting. Supertrope to Mood Ring Eyes. For another unusual way to show emotion, see Expressive Hair. For an extreme example triggered by anger, see Hulking Out. Luminescent Blush, Blue with Shock, Green Around the Gills and No Poker Face are more mundane versions of this. When somebody changes in response to other people's emotions, they're an Empathic Shapeshifter.
- Assassination Classroom: Koro-sensei can change his skin color to show his emotions, since he is otherwise always smiling. He's normally yellow, gains green stripes to show mocking contempt, and turns blue to show shock or sadness, magenta when sleepy or relaxed, white when bewildered, red when angry, pitch black when very angry, and glowing white when extremely angry.
- Kaiju Girl Caramelise: Parts of Kuroe Akaishi's body transform in various ways, ranging from a scaly reptilian hand to spikes along her spine, whenever she experiences strong emotions. She tries to avoid this by being a loner, but her burgeoning feelings for Arata lead to her emotions kicking into overdrive and her sporadically turning into a Kaiju.
- The DCU:
- Green Lantern: The Phantom Ring is a special Lantern Ring that grants access to all parts of the Emotional Spectrum at the risk of draining your life force, and incidentally turns its wearer into this. The wearer's powers and appearance shift to what emotion they're experiencing at the time — so, for instance, if someone is scared their costume becomes yellow and they gain the powers of the Sinestro Corps.
- Loose Cannon (first appearing in the Superman books) grows in strength and size as he gets angrier. He changes color from blue to purple, to red, and finally to white to represent his mounting rage. In his white form, he's barely capable of coherent thought.
- Marvel Universe:
- Excalibur: While Meggan can take on any shape she chooses, her form involuntarily changes depending on her mood, such as becoming more inhuman when she's feeling sad and taking on Nightcrawler's blue skin and hair and golden eyes when they were on the verge of a Relationship Upgrade.
- Runaways: Depending on the Artist, Karolina Dean's skin and hair sometimes glow a certain color to indicate her emotions (pink for love, blue for distress, etc.).
- Chicken Little: The mechs Kirby's alien race pilots have lights that change color depending on their emotion, turning blue when they're docile, yellow when panicking or worried, and red to signal anger.
- Disney Fairies: Downplayed for Tinker Bell, who turns red to express annoyance, but doesn't change colour for other emotions.
- Frozen (2013): Though not living, Elsa's ice castle changes color with her emotions; blue when neutral, purple when happy, red when frightened, and gold when furious.
- Hercules: When Hades gets pissed, his normally blue hair fire turns red.
- Home: The boov change colors to reflect emotions. Red is anger, yellow is fear, orange is happiness, blue is sadness, and pink seems to be affection. In addition, Oh has a bad habit of turning green (possibly with guilt) when he lies.
- The LEGO Movie: Unikitty changes colors depending on her emotion — for instance, she turns red when angry.
- Tangled: While he mostly uses his color-changing to blend into his environment, Pascal the chameleon sometimes changes color on emotions — for example, when he's startled and scared by Maximus suddenly dragging Flynn away, he turns red.
- Harry Potter and the Order of the Phoenix: Tonks' hair. It quickly changes from pink to red after Mad-Eye Moody calls her by her first name. Additionally, it gradually changes from pink to brown after being rejected by Remus and later getting together with him.
- Alice, Girl from the Future: Indicators are animals that change color depending on their emotions, such as turning yellow when mistrustful, dark green when content, and transparent to show admiration.
- The Culture: Drones often display a colored force field to show what mood they're in. They're blue by default, but turn white when angry and red when happy.
- The Dark Artifices: Kieran mixes this with Expressive Hair. His hair changes colors (specifically colors of the sea because his mother is a water faerie) according to his mood, such as dark blue when he's upset or pale blue when he's happy. Usually this is involuntary, but he can sometimes change his hair color at will.
- Harry Potter: Being a metamorphmagus, Tonks' hair changes with her mood, such as changing from pink to brown after being rejected by Lupin.
- A Tale Of...: In Mistress of All Evil: A Tale of the Dark Fairy, Maleficent's skin changes colors depending on her mood. It's a light purple when she's either happy or nervous, but turns green when she's bitter.
- Warbreaker: The Idrian royals have hair that changes colour depending on their emotions. Black for neutral, red for passion, embarrassment or anger, white for fear and golden-blonde for happy or content. They can control it to some extent, along with the length of their hair, which becomes a minor plot point when one of the princesses is trying to conceal her emotions.
- Wings of Fire: One of the reasons RainWings change colors is because of their moods. For example, they tend to turn pink when happy, and they turn blue when sad. It's not purely Involuntary Shapeshifting, however, as they can also change their colors intentionally when they need to.
- Dungeons & Dragons:
- In 5E, an eladrin's appearance changes drastically depending on their current mood. Happiness makes their skin and hair turn green in reflection of spring, anger turns them golden in reflection of the summer's heat, compassion and generosity turn them brown like leaves in the fall, and sorrow or melancholy turn them dark blue like a frozen lake in winter.
- A storm drake's scales change in color based on its emotional state, gaining a pearlescent sheen when the creature is calm, shimmering gold when it's happy and turning a dark, leaden gray when it's angry.
- A flumph's body glows faintly, and the color of the glow changes with its emotional state. Soft pink indicates amusement, deep blue represents sadness, green expresses curiosity, and crimson red shows anger.
- Alkadas, which are normally greenish-blue with purple bottoms, turn red when they become angry or excited.
- Pathfinder: Pyraustas, a type of small insectoid dragons, breathe fire that changes color with their emotions.
- Detroit: Become Human: The androids have circular LEDs in their right temples. Blue is their default color, yellow is for when the android is deep in thought or wirelessly interfacing with other androids, and red is for danger, stress or critical damage.
- Horizon Zero Dawn: CYAN's complex hologram turns yellow when she experiences fear or anxiety, white when she's sorrowful, and green when deep in thought.
- Paper Mario: Color Splash: Huey is a sentient paint can whose black label changes colors depending on his mood: red for angry, blue for sad, purple for surprised, and yellow for happy.
- General Mayhem: Mood Ring is a literal example, and her color changes depending on her emotions.
- RWBY: Ilia Amitola, befitting her nature as a chameleon Faunus, can change her skin, hair, and eye color. Occasionally, her colors will change based on her mood, such as turning red and yellow when she's angry, green and blue when she's sad, or pink when she's embarrassed or lustful.
- El Goonish Shive: In the "Wrong answers only" Q&A segment, Rhea claims that Rhoda transforms according to her mood.
- Girl Genius: As a Spark whose technology operates under Clarke's Third Law, Queen Albia of England can reflexively change her size, appearance, and wardrobe to match the conversation, like manifesting Widow's Weeds when she learns of a death or literally igniting with excitement.
- Abby Hatcher: The Squeaky Peepers are a group of Fuzzlies who change color based on their shared emotional state; if one is unhappy, they all turn blue, and if they're scared, they turn yellow.
- Elena of Avalor: In the final season after Elena is given new powers after falling down a well, her red everyday dress changes its color depending on her emotions and gives an appropriate power; yellow when happy, orange when mad, blue when saddened, cyan when calm, pink when loving, purple when afraid, and grey when doubtful. When she forgives Esteban in the Grand Finale, her dress turns all white.
- The Jetsons: Orbitty's species changes color to express emotions. Yellow stands for fear, pink for affection, black for anger, green for envy, and blue for sadness (although it can also mean "far away" when he's on tracking mode).
- My Little Pony: Friendship Is Magic: When crystal ponies are sad or depressed, they have dull colors and plain, limp and droopy manes. When in better moods and at peace, their colors are brighter and their manes are shinier and fuller. When they're genuinely happy and full of hope, they sparkle like gemstones and become slightly faceted and transparent, and their hair styles change to more elaborate designs.
- Steven Universe: Future: When in intense distress, Steven's gem causes him to turn bright pink all over because his PTSD has broken his ability to differentiate between minor emotional inconvenience and the end of the world. Downplayed, as this is the only emotion that effects a color change.
- Certain animals that can change the colors of their skin often do this to display their emotions to others of their species or to potential predators. For example, chameleons will become brighter when they're feeling excited or black when extremely agitated.