Colour spec of lightGray or darkGray is not respected

Colour names are converted to AWT colours by ColourSchemeProperty.getAWTColorFromName().
This converts the name to lower-case, but then tests for "lightGray" or "darkGray" so they don't match.

For example if you change Pfam feature colour to lightGray in exampleFeatures.txt, and load this on to uniref50.fa, there is a stack trace and the message
Error parsing feature file: java.lang.IllegalArgumentException: Invalid colour descriptor: lightGray
Pfam lightGray