杜隆坦是红皮，而萨尔是绿皮，这两个角色的肤色差异引起了许多人的好奇和思考。为了理解为什么他们有不同的皮肤颜色，我们需要回顾一下《星球大战》系列电影中设定的信息。

在《星球大战》中，杜隆坦和萨尔是两个不同种族的代表性角色。杜隆坦是虾人（Mon Calamari），而萨尔则是杜拉克人（Sullustan）。这两个物种属于宇宙中众多的外星物种之一。

虾人种族的特征是红色的皮肤和鳃状的面部特征。他们来自水下世界，因此皮肤呈现出鲜明的红色，这种颜色可能对于在水下生存的虾人来说具有某种适应性。这是他们的进化方式，帮助他们在水中更好地隐藏和保护自己。

相比之下，杜拉克人的特征是绿色的皮肤和大耳朵。他们来自辛德尔（Sullust）行星，这是一个岩浆覆盖的世界。在这种恶劣的环境下，杜拉克人的绿色皮肤可以提供某种保护作用，帮助他们抵御高温和其他不利的环境条件。

在《星球大战》的角色设计上，为了增加多样性和吸引力，制片方决定将不同种族的外观差异化。这样一来，角色可以更加鲜明地代表宇宙中的不同种族，让观众们更深入地了解这个广阔的星球世界。

总的来说，杜隆坦是红皮，萨尔是绿皮，并没有特定的原因或故事背景解释这一设定。这仅仅是为了创造一个多样化和有趣的电影世界，让观众们在欣赏电影的同时，也能留下深刻的印象。

In the Star Wars universe, Durontan is a Mon Calamari, a species characterized by their red skin and gill-like facial features. They come from an aquatic world, which accounts for their vibrant red coloration – an evolutionary adaptation that helps them blend in and protect themselves underwater.

On the other hand, Sullustans like Saal are known for their green skin and large ears. They hail from the planet Sullust, a world covered in molten lava. In this harsh environment, the green complexion of Sullustans provides them with some form of protection against high temperatures and other adverse conditions.

The decision to have characters like Durontan and Saal with different skin colors in the Star Wars series was likely made to add diversity and visual appeal. By presenting distinct appearances for various alien races, the filmmakers aimed to represent the vast array of species in the galaxy and offer audiences a deeper understanding of this expansive fictional world.

Ultimately, there is no specific reason or narrative explanation behind Durontan being red-skinned and Saal being green-skinned. It is simply a creative choice made to build a diverse and captivating film universe that leaves a lasting impression on viewers.