This was shot in Iceland, starring one of Bollywood's most famous pairs for romantic movies - Shah Rukh Kahn and Kajol. It is breathtakingly beautiful (I love those scarves) and it even has a translation so you can get all the nuances!
When we watched the movie, the translation was "color me the color of saffron" which I took to be the symbolic color of love. One of the things I love about Indian culture is the symbolism color holds (in the same way that I love the Catholic liturgical color symbolism — it adds depth to everything). It turns out that "gerua" actually is an old fashioned term for a color. From Quora:
I have heard this colour described so many different ways....reddish pink, yellowish red, saffron, orange--it seems that every media outlet has taken a shot at what the actual meaning of "gerua" is.Bollynook points out:
When producers were first explaining it and talking about the writing of the song "Gerua", they talked about the ambivalence of opinion on this particular colour and that that was one of the things they liked. The word "gerua" is actual a very old word which was (until Dilwale) almost lost to common use. SRK himself said he like the idea that it was an old-fashioned word because it fit with the film.
The best explanation I have seen is that the colour in Kajol's dupatta when she and SRK are on top of the deserted plane is the colour of "gerua".
This colour is significant here as it defines the purity and sanctity of love and it is compared to Godliness. Hence in a way, it is pointing out that how deep and meaningful love is to the pair.Happy Valentine's Day!