Pengkayaan Materi: Guidelines, Principles, and Theories -> COLOR Course : T0084 – Interaksi Manusia dan Komputer Year : 2013 Pengkayaan Materi: Guidelines, Principles, and Theories -> COLOR

OUTLINE Introduction Strength and limitation References

INTRODUCTION Color is a visual perception Color can get user’s attention Look and feel user interface

STRENGTH AND LIMITATION Our vision is optimized to detect contrasts (edges), not absolute brightness. Our ability to distinguish colors depends on how colors are presented. Some people have color-blindness. The user’s display and the viewing conditions affect color perception

VISION IS OPTIMIZED FOR EDGE CONTRAST, NOT BRIGHTNESS our visual system much more sensitive to differences in color and brightness The circles appear as different shades because their backgrounds are different, but they are the same.

ABILITY TO DISCRIMINATE COLORS DEPENDS ON HOW COLORS ARE PRESENTED Paleness: The paler (less saturated) two colors are, the harder it is to tell them apart Separation: The more separated color patches are, the more difficult it is to distinguish their colors, especially if the separation is great enough to require eye motion between patches Color patch size: The smaller or thinner objects are, the harder it is to distinguish their colors

Example Bad Example: Good Example: ITN.net (2003): Pale color marking current step makes it hard for users to see which step in the airline reservation process they are on. Good Example: ITN.net: The current step is highlighted in two ways: with color and shape.

Example Bad Example: Good Example: Tiny color patches in this chart legend are hard to distinguish Good Example: Large color patches make it easier to distinguish the colors

Example Bad Example: Good Example: MinneapolisFed.org: The difference in color between visited and unvisited links is too subtle.2 Good Example: MinneapolisFed.org: Graph uses color differences visible to all sighted people, on any display.

COLOR-BLINDNESS Having color-blindness doesn’t mean an inability to see colors. It just means that one or more of the color subtraction channels don’t function normally, making it difficult to distinguish certain pairs of colors Red/green color-blind people can’t distinguish: dark red from black, blue from purple, light green from white.

Bad Example MoneyDance: Graph uses colors some users can’t distinguish.

EXTERNAL FACTORS THAT INFLUENCE THE ABILITY TO DISTINGUISH COLORS Variation among color displays Grayscale displays Display angle Ambient illumination

Supporting Material http://www.ics.uci.edu/~majumder/vispercep/student08/colorappearence.pdf Johnson J. (2010), Designing with the Mind in Mind, Morgan Kaufmann, USA, chapter 5