You can change the color of the underline a misspelling.
But it stressed too late and barely visible to those who do not have very good eyes ...
Is it possible to increase the fat that ripple?
In French :
Il est possible de changer la couleur du soulignement d'une faute d'orthographe.
Mais ce souligné est trop fin et à peine visible pour ceux qui n'ont pas de très bon yeux...
Est-il possible d'augmenter la graisse de cette ondulation ?
edited summary notes.
as far as I know the "squiggly red underline" has always been the same thickness since OOo era.
this is enhancement request. maybe an advanced configuration option could be added to set an higher thickness value for it.
status -> NEW