Going a step further:
I see no problem
As a workaround one can define a custom plot:
myPlot[data_, myTitle_, opts___] := ListLinePlot[data, opts, PlotLabel -> Style[myTitle, 18, Black]]
Hmm, it seems that LabelStyle overrides TicksStyle. I wonder why.
LabelStyle
TicksStyle
I just tried
SetOptions[ListLinePlot, LabelStyle -> {FontSize -> 18, Red}, TicksStyle -> {Directive[Black, 20]}, AxesStyle -> Directive[Black, 8] ]; ListLinePlot[ {} , PlotLabel -> "Plot no. 1"]
but I I see no change in the ticks font size. Why?
The option LabelStyle -> {FontSize -> 18, Black} does that, but unfortunately it affects tick labels too, which may be remedied with TicksStyle.
LabelStyle -> {FontSize -> 18, Black}
