Interior LED screens on the 3K/ 6K

I wish i could double flare this but ive noticed on a rare occurrence on 3Ks and 6Ks, the interior LED signage that displays

  GREEN, << DOORS OPEN, DOORS OPEN>>, and the next stop, ive noticed that some of the LED bulbs have been changed from red to Yellow, is this an actual thing rolling out on these cars or are they just prototypes

( i can't really provide images because it looks kind of weird for a person on a crowded train takin a random picture of a LED screen)(especially me with social anxiety)

so yeah has anyone else seen this and can anyone explain if this is going to be a new feature for 3Ks/ 6Ks?