Is there any way/mod to highlight containers or collectible items in Fallout 4? I've searched some forums and cheatsheets, but didn't find any reference. Any idea?
As suggested by DCShannon, the Rank 2 Scrapper perk gives you some ability to highlight collectible items and containers.
At 5 Intelligence, you can invest in the Scrapper perk. At the base rank, it allows you to salvage uncommon parts from your weapons and armor. At the second rank, unlocked at level 23, you will not only be able to salvage rare parts, but favorited components will be highlighted in the game world. This appears to include the containers holding these items, as discussed on this Reddit forum.
This allows you to highlight any item that would file under the 'junk' tab, and any container holding one of these junk items.
To favorite a component, simply access a crafting station, and locate a recipe that contains the component. A message will appear, prompting you to press a button (Y on Xbox, Triangle on PlayStation) to tag any missing components.
Some things to remember:
1 - You can not tag components if you have enough to make the recipe. Either drop what you have in a non-workstation container, find a recipe with higher demand than what you have, or create enough of the recipe to burn your component stash down to a compatible amount.
2 - If you are wishing to highlight all objects, make sure you remove all junk from your workstation. Place all junk from your inventory into a non-workstation container, and proceed through the list of recipes, opting to "tag missing components" at each one. If you are wanting to ensure a "cover all basis" approach, ensure you visit each workstation, as some use unique components. As DCShannon points out, you can also select the component in your junk inventory, and select it for tagging from there.
3 - The different crafting stations are the workshop, power armor station, chem lab, armor station, weapon station and cooking fire.
4 - You do not have to worry all that much about components associated with locked recipes. While there are a few that do not immediately appear, most are available, and simply locked until you have the required perk. You should still be able to assess the material list, and tag as desired.