I've now participated in two broadcast chats. What a wonderful feature.
I live with Familial Essential Tremor which affects about 4% of people at age 40 rising to 20+% of people at age 90; I'm 72 years old. I have difficulty hitting the "Broadcast" button between "Send VMail" and "PSK Rep Map" using the mouse. Yet that whole column is empty below these buttons. Perhaps you would consider making the buttons double in height and floating so they could be reordered by the user. I would put the "Broadcast" button above the other two.
Another possibility is the use of the keyboard. Many of Google's web-based programs include keyboard combinations for various actions.
Many of us are familiar with blind hams and I'm told VarAC has worked with screen readers. There are other disabilities that could be accommodated in the user interface if some input was obtained. Color changes and font sizes are useful, but not the whole story of the user interface.
Thank you for accepting this suggestion. I hope it will receive consideration for inclusion in a future upgrade.