I don't know the colour coding of Organ needles, but there are lots of differences between needles. First the size 75/11 is smaller than 90/14. An 80/12 is a needle used for cotton etc, 90/14 for jeans. The most used sizes vary from 60 (for organza) to 100 or 110.
Then there is a difference in the points of the needles. There is one called Universal; there are Ballpoint needles and SUK are for stretchy materials and jersey, extra sharp ones for jeans and denim (in size 90) and for quilting (in 75 and 80); the so-called top stitch ones and special leather needles.
There are needles with extra large holes: for embroidery (often coloured red), even bigger holes for metallic thread and woollen yarns.
In short lots of variations!
Ask your dealer, he stocks all sorts and can explain which needle to use for which job.

The numbers indicate size, 90/14 is the most common size usually used on medium weight fabric. The 75/11 is a fine needle used on finer weight fabrics. Not sure on organ needles, but on singer needles the color indicates whether it is a needle for woven fabric or knits. Hope this helps.

Got your answer, just know that there are more types that we can ever use.
Have a great day with you needles,
Michelle

Here is an "Sewing Machine Needle Charts" link.