Illegal string offset 'hex' in /style.cls.php line 1419

[nasy]

Using php 5.4 or higher:

ContextErrorException: Warning: Illegal string offset 'hex' in /Applications/MAMP/htdocs/.../vendor/slik/dompdf-bundle/Slik/DompdfBundle/DomPDF/include/style.cls.php line 1419

The issue is in the version of dompdf used in this bundle:

$this->_props["color"] = $col["hex"];

This is fixed in dompdf 6.0. Is there a way to update the dompdf version using the bundle config (not changing the files manually) ?