Node colors (add hue, invert option)

The hue nad invert atribute should affect the output color.

.graph-view.color-fill-tag {
 color:var(--color-accent-hover) !important;
 filter: hue (280);
}

or

.graph-view.color-fill-tag {
 color:var(--color-accent-hover) !important;
invert: 70%;
}

This option will enable more color-responsive graph themes to be created. As we have many different nodes it is important to dynamically change the color - when the main accent color is changed.