Would be helpful if you could tell us what kind of footage you're starting with, and what your "properties" settings are, and what your render settings are.
Might be an upper/lower field issue, but we won't know until you offer more information
Be aware that the color space of the NTSC DV codec isn't as good as most other codecs, and can look "washed out". I pretty much never use the DV codec any more because of this.
You might be rendering to the DV codec that comes with Windows (which pretty much sucks quality wise) instead of the high quality one that comes with Vegas.
It's true that the colorspace of the DV codec is only 4:1:1 but that doesn't cause a "washed out" look. What it does cause are block artifacts if you are trying to use highly saturated solid colors on a contrasting background, like bright red text on a black background. This is a limitation of all DV codecs, otherwise the one in Vegas is much better than any other DV codec out there.
You might be rendering to the DV codec that comes with Windows (which pretty much sucks quality wise) instead of the high quality one that comes with Vegas.
This brings up a question I have wondered for a long time. How do you know whta codec you are rendering with. What I mean for example is if you have had (for what ever reason) 3 different DV codecs on your machine, how do you know which one it is using?
If you are rendering from within Vegas and under "Options" > "Preferences" > "General", the "Ignore third party DV codecs" setting is checked and "Use Microsoft DV codec" is unchecked, then you are using the Vegas DV codec for encoding and decoding.
As far as having three additional DV codecs installed, only the one you installed last would ever be active outside of Vegas. In Vegas, only the Vegas DV codec will be active..
I don't see the two options under:
"Options" > "Preferences" > "General", the "Ignore third party DV codecs" setting is checked and "Use Microsoft DV codec"
It looks like SCS moved the DV codec settings to internal. Hold down the shift key and click on Preferances. Select the Internal tab and type codec in the 'Show only prefs containing' box. You should find Ignore third party DV codecs = True and Use Microsoft codec = False. Don't change anything else unless you know what your are doing.