I'd like to hear from those who've tried matching nail polish to their tired and rusted frame paint (in this case, a sky blue). I have a Pro Miyata that's spent real time out in the rain. A lot of rust. Brake cable guides especially. I don't think it's structural but it is quite visible in quite a few places. I bought this frame from a BFer who linked an excellent set of pics so it came with no surprises. (Well the seat pin threads gave out on the second seat height adjust but given what I knew, not really a surprise.)

I want to ride this bike without fear of further rust damage without a major commitment of dollars or downtime. It doesn't need to impress anybody. All I want is the ride! Between my legs, it is one of the sweetest, fastest, best behaved bikes I've ever ridden; may be the most for all of those. Very obviously a bike built very close to the peak of small diameter steel race bike excellence. The tubes! Miyata's in-house so I don't know what they are and cannot boast about them, but again - the ride! The geometry - pure race and as sweet as you can ask. I have no idea how fast is too fast and I will never live to see it.

Stop gushing, Ben! Enough about the bike. So, I'm looking for flesh toned bandaids, not a makeover. Ideas?

So, are there nail salons that can do color matches? Or ones with the best selection of stock colors. (In sky-like blues?) Any hints on where to start?

Take your frame to the nail polish counter and look for a match?

I just take my frame into Sally Beauty Supply. They have like 300 shades of nail polish.

I have said that about your nails.

It is too thick in the container. Thin it down a bit with acetone or nail polish remover.

I've been through this process - didn't want to ruin the original paint with a bodge so got some nail polish and made ok repairs which are removable and stop any further rust.

I photoed the original paint to get an RGB value then looked online for a matching nail polish, difference is difficult to spot from 5 feet.
Some rust spots I didn't paint, just rust converted then used the nail polish top coat to seal the paint.

I found Mavala nail polish to have a good range: https://www.mavala.com/en/910-mini-color
Select 'blue' in groups of shades.

Been there and done that. Nail polish is not made to be long lasting due I suspect to chipping, wear, etc. and so the colors fade over time rather quickly unlike enamels or lacquers. I ride through lots of parking lots looking for vehicles colors that might match the bike and if found can get touch up paint that holds up very well.

Nail polish is workable if you thin it and you are comfortable with something that dries very quickly. It is good at filling low spots caused by paint chipping, but is also brittle. From the bottle, it is very thick.

Another option is automotive touch-up paint. It's like nail polish, though more durable. It also dries quickly and usually has to be thinned with acetone. It gets expensive to do it this way, but if you have a good match, it's an option.

Take a look at Testor's model enamels (the oil-based). It's easy to mix, not overly expensive, and the dry time is more moderate. It also comes in numerous colors in tiny bottles. The durability is just so-so, but once you have a recipe or color that works, it's not hard to patch up. I use disposable plastic eyedroppers to mix until I have a recipe that works for my bikes.

I take the fork into a CVS/Walgreens/RiteAid, and look for a close match.
Sometimes the fork shaft has original paint on it, and I dab there to see a final match.

Another option are auto paint supply stores. Most have color matching, and some even make custom aerosol cans.

Before paint I would use this , not only will it stop the rust it will also build up the bare spot and level it out some .

For years I have had a bottle of clear nail polish and used it to touch up paint on cars and bikes. Nail polish has a lacquer base and so is very effective in creating an air barrier to prevent corrosion. Even Campy chrome plated components develop rust over time and best approach is to replace them with new parts.

Another big fan of Testor’s here. Get the multi color kit from Amazon and a set of quality small pointed brushes. I mix mine on a heavy duty Ziploc bag so I can get the shading just right. Silver adds metalflake, black makes it a little darker, white a little lighter. Have yet to find a shade I can’t touch up nicely.

How do you keep it from drying so quickly while mixing?

Some of the Testors paints were discontinued in 2020 when Rust-Oleum bought them out.

Just thankful you can still get PLA. Marvelous hobby paint.

I looked for a year until I found a good match in nail polish for Raleigh Coffee. There used to be a paint code floating around the forums for Raleigh Bronze Green, it was for a Ford Pinto. And GM copied Raleigh Chartreuse for the mid-70s International, putting it on Olds Cutlasses.

Doc, I really appreciate this suggestion. I've had great luck matching non metallic colors with Testors but when I mix the metallics they turn muddy. I'll try your method of adding silver to non metallic colors.
Brent

The color kit comes with a bottle of thinner. Ofherwise, I just move quickly.

Makes sense. I have fun when mixing for funky fade colors...I am still trying to master that.