Lovegood's hair

[xuxunette]

Hello guys,
Joined this group to ask a urgent question. 

I'm not a native english speaker and one thing has always had me
confused, what does 'dirty-blond', Luna's hair color, means exactly?
Is it darker or lighter than regular blond?
Is there a the difference between 'dirty-blond' and 'straw-blond'?

Also, additional question, I always understood 'straggly hair' as a
kind   straight hair with some curls, only messed up, but I keep
seeing fanart depicting her with straight and very smooth hair. Am I
again misunderstanding the term?

Sorry to bother you with those capillary introspective, but hair are
important! ;)