There are two aspects to it. One is the colour change during ripening. eg. Chillies change colour as they ripe from green to black and then to red. Other aspect is the genotype. And for obvious reasons, there is a difference in characteristics in both of the above aspects due to change in colour.

You do not know what actually is different to the colours of paprika?

Colour is one of the indicator of the different in chemical composition content of commodities. Different composition contributed to different characters, quality and storage life of commodities. The difference may be slight or significant depend on many factors. Each types of varieties should be studies to understand the strength and weakness of each varieties.

Generelly, some red characters of fruits related to their biochemical component. For example, the dark yellow carrot has more carotene the light yellow. However, there are excepts.

So besides carotene no other difference in vitamins and/or minerals, or not-nutrients (is that the correct term? although carotene is a non-nutrient of course)

I think that your subject suggested is true generally, but there are excepts, for example among peach varieties. Some of them have suitable red color, but no good delicious but the others vis viz. We must follow these excepts. Science is beautiful because of this.

Well sometimes it is claimed that a healthy diet (part of it) consists out of eating fruit/veggies from each colour group. Paprika has different colours (red-green-yellow/orange) so they either have different features or it is just a myth in a sense. So variety might have a role?

For instance I eat most green veggies, but if I look at the colour advice I would not be varied enough. That was also part of my question

Hi Dear peter

I"m working on the effect of high temperatures on some biochemicals characters in olive leaves special organic acids such as malic acid, oxalic acid, salisilic acid and citric acid , but allmethods in articles  read are about the fruit. In other hand, their material requirements are so expensive to set those for leaves. I'm terrible and haven"t enough time either. 

Thanks.  

 I wonder if you help me by sending some article worked special on the leaves.

Dussi, C., D. Sugar, T. Righetti, and A. Azarenko. 1997. Effects of cooling by overtree sprinkler irrigation on fruit color and firmness in ‘Sensation' Red Bartlett pear. HortTechnology 7:55-57.

Dussi, C., D. Sugar, T. Righetti, and A. Azarenko. 1997. Colorimetric characterization of red pear cultivars. Fruit Varieties Journal 51:39-43.

Dussi, M.C., D. Sugar, R.E. Wrolstad. 1995. Characterization and quantification of anthocyanins in red pears and the effect of light quality on fruit color. J. Amer. Soc. Hort. Sci. 120(5):785-789.