Lots for Sale - this contains colors in which current part is being listed for sale.
On Wanted list - this shows which colors Bricklink members have added to their "wanted list". It doesn't mean parts in this color have existed. Most likely this being used to add non-existing color to list of wanted items and mark for notification. In such case if wanted ...
The best way to figure out what colors a set of parts have in common is to use BrickLink’s Stud.io digital design software. I am unable to show screenshots at the moment, but here are the steps:
Place the parts in question on your virtual building workspace (doesnt matter in which color)
Select all the parts together, either by:
using the ...
As Alex mentioned, part of the variance can be attributed to yellowing, especially the ones pointed at with the arrow. For the remainder, I think you are looking at variations in color introduced in the production process ... see this question for more details: LEGO color discrepancies and tint variations
Unfortunately, you need to check available color for each individual part:
From what I can see most of the colors 11203 comes in are available in other parts as well.
Following your edit I can suggest another option for you - Color Guide. Select a color and click on Parts column to find all parts available in particular color.