What can I use on pallet wall to stop chance of splinters?

I can't see the end of your question, but if you're saying you don't want the color of the wood to change, you can use Polyacrylic - it's a clear coat sealer - I'd try it on a scrap piece of the same kind of wood though - sometimes it may make the wood;s natural color a shade or two darker, but nothing that drastically alters the wood's color; everything on which I've used it has brought out the character & depth of the wood.

To eliminate splinters you may need to give the wood a bit of sanding... just enough to get rid of the roughness... 80 grit should work

Splinters come from inferior wood... it wasn't planed completely, and may Always splinter.

You can sand it down and then apply a finish on top

Clear Acrylic varnish should do it, after you have sanded down the rough bits of timber.

You will need to sand it smooth.

You would do well to sand the wood and then use a matt sealer.

Before you start assembling your materials, you will need to sand them down to get rid of any rough edges and avoid splinters. Make sure you have enough space and good ventilation, ideally working outside. It's also a good idea to lay down some dust sheets.

Lightly sand and spray with Matt clear coat.

Add a water-based clear coat.

Hello Susana: If you sand it and put some acrylic on it. Here's a site that should help: How To Seal Pallet Wood - Step-by-Step Guide | Cut The Wood