Imaris: Remove empty color entries for non 0 indexed colors

[dgault]

Issue was raised on forum thread https://forum.image.sc/t/how-to-open-ims-files-with-fiji/29907/12
A sample file was provided on https://zenodo.org/records/11203497 and can be used for testing

The problem appears to be due to the colors in the file being indexed from 1 rather than 0, this lead to a null entry in the arraylist. Removing the empty entry allows for the file to read without exception.

To test, use the sample file in the Zenodo link

• Without this PR attampting to initiate the file should result in an exception as below
• With the PR the file should be read without the exception and the images display as expected

	at loci.formats.in.ImarisHDFReader.initFile(ImarisHDFReader.java:413)
	at loci.formats.FormatReader.setId(FormatReader.java:1480)
	at loci.plugins.in.ImportProcess.initializeFile(ImportProcess.java:498)
	at loci.plugins.in.ImportProcess.execute(ImportProcess.java:141)
	at loci.plugins.in.Importer.showDialogs(Importer.java:156)
	at loci.plugins.in.Importer.run(Importer.java:77)
	at loci.plugins.LociImporter.run(LociImporter.java:78)
	at ij.IJ.runUserPlugIn(IJ.java:244)
	at ij.IJ.runPlugIn(IJ.java:210)
	at ij.Executer.runCommand(Executer.java:152)
	at ij.Executer.run(Executer.java:70)
	at java.lang.Thread.run(Thread.java:748)

[imagesc-bot]

This pull request has been mentioned on Image.sc Forum. There might be relevant details there:

https://forum.image.sc/t/how-to-open-ims-files-with-fiji/29907/18

[melissalinkert]

h5dump -A on the file shows that Channel 1, Channel 2, and Channel 3 have a Color attribute, but Channel 0 does not. showinf -nopix -omexml with this PR shows that channels 0, 1, and 2 have a Color set, but channel 3 does not.

[dgault]

With the first commit, removing the empty colour resulted in the remaining colours being re-indexed. With the latest commit the null colour is now handled so the previous colour indexes remain intact.

[melissalinkert]

This looks good to me. OK to merge if builds are green in the morning.