How to keep the colors from RAW files in JPG?
As mentioned above, you need to set a Camera Profile setting for Nikon Standard, or whatever your perference is. Do some side by side comparisons between Nikon Capture and Lightroom, adjusting the lightroom develop setttings (saturation, Nikon profiles, etc) until they look the same. Then save these settings to a User Preset. You can configure Lightroom to use this preset on all photos you Import automatically. Alternatively you can selective apply the Preset(s) you create to any batch of photos.
This gives you the results you liked out of the Camera with RAW files, replicated closely in Lightroom.