I've read on Matt's blog on many occasions where he points out domains which have multiple hyphens, as spam sites.
Please keep in mind that I am not saying having a single hyphen is bad. Two is probably ok too, but once the domain has three or more hyphens then it would at least be suspect in my book. I personally would not click on a link which has a multiple-hyphen TLD. So even if the search engines don't see 3 or 4 hyphens as a problem, why risk not getting someone's click?

I work for an SEO company, and do optimizations. My experience has been that hyphenated domains don't do as well. We don't even accept sites with more than 2 hyphens. 99% of the time the hyphens are there for keyword spamming.

wellcome to www.0058.net

I agree with the comments that domain names should not have more than one hyphen. One thing that you should be really carefull about is how the domain sounds if you are telling it to someone.

I doubt you would find much difference in Google, as I don't think that keywords in the url are weighted that heavily. Google cares more about inbound link text relevance, title tags, and H tags.

I've found that long URLs (whether it's a penalty or not, I don't know) have overall lower page rank than short, descriptive URLs. Another good reason to go with your /widgets/blue/fuzzy method is because Google will NEVER look at it as "Keyword Stuffing". The other method, if it isn't penalized now, might be some time down the road.
Even better, though, is to keep your pages up high and don't go too deep into a directory structure as PR goes down for each / in the URL. Your BEST solution would be:

/widgets/blue_fuzzy.html
/widgets/red_fuzzy.html
/widgets/blue_smooth.html