See below. A lot depends on the device being used. I mainly use an iPad mini where the text is very small. Oddly enough the same text is perfectly readable on my iPhone5 as the text is actually larger despite it being a much smaller device. If the wind gust text (numbers) were the same size as the wind text it would also solve the problem.

A lot depends on the user’s eyesight of course.

The gust speed font size is small and black text on a dark red background is unreadable e.g. at 30kts.

Can contrasting background and text colours be used? I realise this may be difficult, so perhaps there are alternative presentations, such as black text with a white drop shadow?

(Sorry if this is a duplicate but searching on “text” and “colour” returns too many hits!)