Better default channel colors

[frasercl]

Use Case

Scientists want to have the channel colors that are best for reviewing data either applied by default or easily available to apply.

Solution

Caroline described the ideal colors as:

• If two channels are being compared, one should be green and the other should be magenta
• Bright field channels, and/or channels which are the only ones in the dataset, should always be gray

Options for implementation include:

• Add a color palette like the one described above to the "apply palette" menu
• Apply that palette by default, or even get a little smart about testing against the rules described above
• Allow default palette application behavior to be context-dependent, so that e.g. CFE can maintain its more pleasing but less analytically useful default colors