Sourcing the origin of the word orange will have most people running in circles. Firstly, it is not the fruit which is named after the colour. The colour (which was until then named ġeolurēad or yellow-red) was named after the fruit. The word for the fruit can be traced all the way back to one of the Dravidian languages - Tamil (நாரம்/nāram), Telugu (నారిఙ/naarinja), Malayalam (നാരങ്ങ/naaranga) - and then via Sanskrit where नारङ्ग (nāraṅgaḥ) represented the orange tree. The word subsequently appears to have taken a route through Persian (nārang), Arabic (nāranj), Italian, Spanish (naranja) and French (orenge) before finding its place in English.
On a related note, a variant of oranges found in South Africa named Naartjie (in Afrikaans) is said to have its etymological roots in Tamil with the word nārattai (or nartei) meaning citrus.