1a. no restrictions
Explanation: With a color scheme of no restrictions for 3 group of data; Red-Green-Blue are the more relevant colors to differentiate the groups easily.
1b. color-blind safe
Explanation: With a color scheme of colorblind safe; Red color is not preferred.
1c. photocopy safe
Explanation: Photocopy safe indicates that a given color scheme will withstand black and white photocopying. These colors were used to easily distinguish when the graph is photo copied.
2a. no restrictions
Explanation: Using these colors with reference to conference so as to differentiate 5 different conferences.
2b. can you do a color-blind safe or photocopy safe version? why or why not?
3a. choose a multi-hue colormap
Explanation: Ranking is a sequential attribute. In this graph, dark color is used for high rank to light color for low rank.
3b. choose a single-hue colormap
Explanation: Ranking is a sequential attribute. In this graph, high saturated color is used for high rank to low saturated color for low rank.