lecture 3 - Understanding colour

Chromo Tool and Color Attributes

Introduction to Chromo and Free Sort Exercise

• Chromo Tool Overview: An interactive tool with options for free exploration, adding $36$ colors, and adding $9$ grayscale tiles.

• First Exercise: Free Sort:

  • Users are instructed to arrange the provided color tiles in any order they like (grouping, separating, making patterns).

  • The purpose is to freely explore and play around with the tiles; there is no right or wrong answer.

  • Action: Take a screenshot once satisfied and upload it to Padlet.

• Clarification on Marking: In-class exercises and direct Padlet uploads during class time are not for marks. The screenshots are for homework, which is due the following Tuesday.

• Troubleshooting: Instructions were given for clearing tiles, selecting specific challenges vs. exploration mode.

• Color Perception Variability: Noted that colors might appear slightly different across various computer screens or devices.

• Padlet Review Examples: Discussed various approaches to the free sort, including:

  • Linear arrangements, often separating achromatic colors from red/orange hues.

  • Grouping pale and dark colors.

  • Separating colors by hue (e.g., greens in one corner, purples in another).

  • Arranging vivid, dark, muted, pale, and achromatic colors in distinct sections.

• Key Term Introduced: Achromatic colors, referring to black, white, and gray, which lack hue.

Achromatic vs. Chromatic Sort Exercise

• Second Exercise: Separate achromatic colors (black, white, gray) from chromatic colors (the $36$ color tiles).

• Arrangement: Achromatic colors on the left, chromatic colors on the right.

• Action: Take a screenshot and upload to Padlet.

• Consideration for Limited Color Vision: Individuals with limited color vision should sort what they perceive as achromatic or muted colors on one side and the rest on the other.

Hue Family Sort Exercise

• Third Exercise: Sort colors into Hue Families.

• Setup: Clear the screen, navigate to the menu, and select the "sort hue family $16$ colors" challenge, which presents tiles in a diamond shape.

• Diamond Arrangement Rule: For each hue family, arrange tiles such that:

  • Vivid color is on the right.

  • Dark color is on the bottom.

  • Pale color is on the top.

  • Muted color is on the left.

• Feedback Mechanism: Tiles click into place; mistakes cause the tile to pop out, and a timer tracks performance.

• Starting Point: Begin with $4$ hue families to practice.

• Action: Take a screenshot and upload to Padlet.

• Advanced Options: After completing the $16$-color sort, users can attempt the full $32$-color sort or manually place all chromatic tiles on the board and perform a full family sort for a greater challenge.

• Context for Differentiation: When distinguishing similar colors (e.g., two greens, blue/turquoise), context is key; seeing all colors together makes relationships more obvious.

• Importance of Hue Families: The $9$ hue families provide a good basic set for familiarizing oneself with a range of colors.

Color Character Sort Exercise

• Fourth Exercise: Sort colors by Color Characters.

• Setup: Clear the screen, return to the menu, and select the "sort color characters" challenge ($16$ or $36$ colors).

• Arrangement Rule: Similar to the hue family diamond, but applied to color characters across different hues:

  • All vivid colors go to the right.

  • All pale colors go to the top.

  • All dark colors go to the bottom.

  • All muted colors go to the left.

• Purpose: This creates a strong visual representation of how different character types (vivid, pale, dark, muted) appear and can evoke specific feelings or emotions.

• Emotional Associations: Discussed connections between color characters and emotions:

  • Intense feelings associated with vivid colors.

  • Less intense feelings with pale colors.

• Seasonal Associations: Common associations were made:

  • Vivid: Summer

  • Pale: Spring

  • Dark: Winter

  • Muted: Fall

• Communicative Ability: Emphasized that character-based color associations are often more impactful in communication (e.g., design, clothing) than hue-based associations.

Color Attributes: Hue, Lightness, and Chroma

• Definition of Color Attributes: Perceptual qualities that collectively define a color's appearance. There is no single universal system for organizing all colors; the choice depends on specific purposes.

• Key Attributes for this Class: Hue, Lightness, and Chroma.

• Hue:

  • Definition: The quality that describes a color as reddish, yellowish, greenish, or bluish; it is the most salient characteristic of a color.

  • Relationship to Spectral Range: Refers to how a color fits within the spectrum and the color circle (red, blue, yellow, green).

  • Presence: All colors possess a hue, except for achromatic colors (black, white, and grays).

  • Distinction from Color: "Color" is the overarching concept, while "hue" is one specific attribute of a color.

  • Near Neutral Colors: Colors that are very muted and close to gray, often described with a faint hue (e.g., bluish gray, reddish gray).

• Lightness (or Value):

  • Definition: Describes how light or dark a color appears.

  • Grayscale Equivalency: Can be visualized by converting a color image to grayscale; the corresponding gray tone indicates its lightness.

  • Scale: Ranges from white (highest lightness) to black (lowest lightness).

  • Reflection Properties: White reflects almost all light; pale colors reflect a lot; dark colors reflect little; black reflects nearly none.

  • VantaBlack: The world's blackest known substance, a nanostructure created to absorb almost all light.

  • Whitest White: Found on a specific moth from the Amazon, reflecting almost all light.

  • Visual Examples: Showed how different hues can share the same lightness (e.g., a scarf and sweater).

  • Homework Connection: Students will gain practice by sorting hue families according to lightness, matching colors to their grayscale partners.

• Chroma (also referred to as Saturation or Purity):

  • Definition: The degree of colorfulness or vividness of a color, judged against an achromatic gray.

  • Characteristics: High chroma colors are pure, intense, or saturated; low chroma colors are dull or diluted.

  • Achromatic Colors: Lack both hue and chroma, possessing only lightness.

  • Near Neutral Colors: Possess very low chroma (e.g., very pale grayish-green).

  • Real-world Example: The varied range of chromas and lightnesses seen in an apple, from vivid reds to low-chroma greens in the leaves.

  • Max Chroma Variability: The maximum chroma attainable for a given hue varies:

    • Yellows tend to have the highest chroma, appearing most vivid.

    • Blues and purples typically have lower chromas.

    • This difference is attributed to the human eye's higher receptivity to yellow light, as it aligns with the peak energy output of the sun. Our cones are maximized for yellow perception.

  • Visual Representation: Discussed an image showing lightness on the y-axis and chroma on the x-axis, illustrating that a color can be dark but still high-chroma (e.g., a dark, pure red).

  • Digital Color Example: Setting red to its maximum value ($255$) and blue/green to zero yields a high-chroma red. Decreasing the red value (e.g., $200$) makes it darker (lower lightness) but maintains its high chroma.

  • Image Analysis: Identified high-chroma elements (e.g., green wok, yellows) and low-chroma elements (e.g., background colors, grayish-blues).

  • Homework Connection: Students will practice chroma sorting, typically by arranging colors around a central grayscale, with vivid colors furthest away and muted colors closer to the gray.

Three-Dimensional Color Models

• Limitations of $2D$ Hue Circles: Relying solely on $2D$ hue circles is restrictive and cannot fully represent the complexity of color perception.

• Advantage of $3D$ Models: Arranging colors in three-dimensional shapes allows for a much more comprehensive representation, as colors possess three perceptual attributes (hue, lightness, chroma).

• Hue Planes (or Extended Hue Families): These represent all variations of a single hue, showing how it can become paler, darker, or grayer.

• Color Mondo Demonstration: A physical $3D$ color model was passed around:

  • Structure: Spherical.

  • Hue Circle: The outermost ring displays a standard hue circle.

  • Lightness Axis: The top (North Pole) represents white (pale colors); the bottom (South Pole) represents black (dark colors).

  • Chroma Axis: Each pull-out segment represents a hue family. Colors move from vivid on the outside towards gray in the center.

  • Benefits: Offers a superior visualization of color relationships compared to $2D$ wheels, showcasing more variations.

  • Future Activity: Students will build their own Color Mondo models in a future class.

• General $3D$ Model Layout: Includes a hue circle (primary structure), with chroma decreasing towards a central grayscale, and lightness increasing upwards towards white and decreasing downwards towards black.

• Asymmetric Systems (e.g., Munsell): Some models, like the Munsell system, are asymmetric, reflecting how maximum chroma varies by hue.

• Hue Plane Axes: In a typical hue plane, the x-axis represents chroma (from achromatic to vivid), and the y-axis represents lightness or value (from dark to light).

• Construction: $3D$ models are composed of many such hue planes (segments), which can number $9, 12, 100,$, or even $1000$ for very detailed systems.

• Importance and Applications: These organized color models are crucial for:

  • Manufacturing: Precisely specifying colors for products (e.g., paint, textiles), particularly vital after the Industrial Revolution.

  • Standardization: Ensuring consistency in color communication, such as the red used for train stoplights.

  • Numerical Specification: Each system assigns three specific numbers (for hue, lightness, chroma) to uniquely define any color.

• Munsell System Details: An example of a specific $3D$ system:

  • Hue: Subdivided into $100$ hues.

  • Value (Lightness): Scale from black ($1$) to white ($10$).

  • Chroma: Variable scale, starting at zero (grayscale center) and extending outwards. Yellows can reach higher chroma values than blues or purples.

  • Designation Example: 5R 7/8 indicates a specific hue (Red: $5R$), value ($7$), and chroma ($8$). This system, developed in $1905$, remains a standard for color specification.

Traditional Color Theory and Misconceptions

• Context: Traditional color theory is often taught in reference to mixing paints.

• Limitations of $2D$ Color Wheels: They are restrictive and do not encompass the full range of color variations or the interdisciplinary nature of color perception.

• Focus of Class: To train the eye to recognize all three perceptual attributes of color using $3D$ visualizations.

• Primaries (Traditional Concept):

  • Definition: A minimal set of colors (e.g., Red, Yellow, Blue - RYB) from which all other colors can supposedly be mixed.

  • Misconception: It is theoretically and physically impossible to mix all perceptible colors from just three primaries.

  • Problems with RYB: Ambiguity in "which" red, yellow, or blue to use; no single unique or correct set exists.

  • Other Primary Sets: RGB (Red, Green, Blue) for computer screens and CMYK for printing are also used, each corresponding to different mixing processes (additive vs. subtractive).

• Secondaries: Colors mixed from primaries (e.g., orange from red and yellow).

• Complements: Opposites on a color wheel; however, there is more than one way to define a complement.

• Terminology for Paint Mixing: Reflects how colors are made rather than how they appear:

  • Tint: A pure hue mixed with white paint, resulting in a paler color.

  • Shade: A pure hue mixed with black paint, resulting in a darker color.

  • Tone: A pure hue mixed with gray paint, resulting in a muted color.

Homework Assignment

• Due Date: Next Tuesday.

• Tool: Chromo.

• Tasks: Perform lightness and chroma sorts as per directions provided in a separate link.

• Submission: Hand in four images (screenshots) on a single surface, including:

  • A hue family sorted by its lightness, aligned with its grayscale partners.

  • A hue family sorted by its chroma, arranged around a grayscale (vivid far, muted close, dark/pale in between).

• Reference: Exercise layout and examples are available on a provided website link.