I usually get my filament from Pushplastic.com.  Their regular orange is pretty bright, but probably not enough for your purposes.

Someone gave me a spool of filament from HobbyKing for a Christmas present once, and it was pretty good stuff.  Here's a link to some of their neon orange: https://hobbyking.com/en_us/fluorsecnet … range.html. 

It's hard to tell from just a photo, but it seems pretty vibrant.  By comparison, best tool backpack for electrician looks brighter than their regular orange.

Thanks for the link!

Technically, there is no official shade of Orange, the PPE suppliers I worked for, dealing in thousands of hard hats, hiviz jackets, traffic cones by ton and anything reflective like Class 1 Diamond Grade and Class 2 Reflective.

Anyway... As long as its an eye popping orange, has got a fluorescent radiance to it, you can't go wrong. 

I got a 3D Printz reel of their bright fluorescent orange, makes nice prints too.

http://greybeard3d.com/

Someone gave me a spool of filament from HobbyKing for a Christmas present once, and it was pretty good stuff.  Here's a link to some of their neon orange: https://hobbyking.com/en_us/fluorsecnet … range.html. 

It's hard to tell from just a photo, but it seems pretty vibrant.  By comparison, it looks brighter than their regular orange.

https://atomicfilament.com/products/1-k … a-filament

There are plenty of options available just google hunter orange, neon  orange  florescent orange or safety orange. filament.