New Sheild Plus and looks like the front white dot sight is a little less than pristine. Want to touch it up.

S&W customer service recommended white nail polish. Anyone have a better suggestion or is that the best way to do it?

Here’s a pic of what it looks like now.

https://postimg.cc/ZWRYD59h

Of the various ways, a popular one is to use Gloss White model car paint.
Fingernail polish will work and dries faster.  You can buy it in most any store and it's cheap.
In any case shake it very thoroughly to fully mix.

To apply, dip a toothpick or fine artist's brush in the paint and touch it to the dot.
Before applying it use some 91% alcohol to degrease the sight and dot or it won't last.
After it's TOTALLY dry apply some lube to prevent rust.

Thanks. Have you tried both model paint and nail polish? Any preference?

I always used model paint simply because I always had it available.

I understand that fingernail polish may be harder and more durable and dries faster.

I have used paint pens prior and have had good luck with them.

Lacquer stick

I've had good luck with the toothpick and model paint method described above.  Clamp the slide so that the rear surface of the sight is horizontal to keep the paint in the recess for the dot.

I use the the brightest florescent orange nail polish I can find along with the toothpick. I also black out the rear sights so my eyes only focus on the front sight and not wast time trying to line up the dots.

I was going to get some better HD sights like the Trulglo TFX Pro.  I may try your method first. Won't give night visibility, but will be better than the atrocious white dot.

For some reason I have not been impressed with the TFX line by TRUGLO but their Pro Night Sights are outstanding. The amount of bright green glow is amazing at night and in low-light. I have the White Dot Front on one of my 2.0C's and VTAC Sights on my other 2.0C. I just ordered the Orange Front TRUGLO Pro's for my new Shield Plus. The Pro's come with blacked out day-rear night sights. I also have the regular TRUGLO Night Sights on a 1.0 compact which have day white-rears which admittedly don't naturally guide to the front sight post like the Pro's but still work. I do love my VTAC Sights but honestly I can shoot just as good with the TRUGLO Pro's for 50% less in cost.