Feature request: set font style, link color and gene color

[clf-bio]

Clinker is a great tool for comparative genomics. It would be even better if it could:

1. Change font style (eg label), eg italic or bold
2. The default higher limit of link color is black which makes hard to read the label text. Could the users be able to change the higher limit of links color, eg, to grey?
3. Set the color of multiple genes at one time