How come tribes from Hawaii, Papa new guinea, Bahamas, Tonga, African, Australia or basically any tribe located on islands are so similar? This does not only have to do with skin colour, if i were to google and search from images from each tribe they would look very similar when it comes to their choice of clothing and makeup, even if they have never ever met eachother before.
They're not really. The similarities would be mostly superficial. To an outsider, the differences get swept aside and it's hard to appreciate what makes them unique. If you showed an outsider random pictures of the cities of Chicago, Los Angeles, and London, they would all see modern, western cities. They'd all have high rises, similar fashions, and they'd all sound pretty similar. Ask somebody from LA what they have in common with London and that'd be about it. The actual culture of each place is unique but cherry picking random pictures of the people that live there isn't a good way of experiencing them.
Does this help?
Could you share some examples of things you'd consider similar? You're making a very broad assumption, so we can give a much better answer if you point out specific elements of similarity between two groups. At the moment, this seems to be an uninformed assumption based on biased, ignorant stereotypes.
Many things appear similar for two reasons:
Practicality: Most places you go, bowls are round and spears are straight, not because of any connectivity, but because round ceramics are easier, scraping food out of a corner is a pain, and throwing a pointy "L" at a deer isn't terribly effective. Same goes with the stereotypical "tribal" things. If you need to make a leg covering with natural materials, some people are going to make similar things in different places because they're accomplishing the same task. Likewise, certain patterns and designs we lump as "tribal" have similar features because they use the same basic weaving techniques. Looking at details, you'll see that there's great variance beyond basic forms. When doing cultural comparisons, we must always to not ascribe significance where non is due.
Cultural Perspective: Try explaining to someone the difference between a tuxedo and a suit. You'd never wear a tux to a business meeting, but could anyone know that by looking? The physical appearance of something is only part of it: you must also consider its cultural role and actual function.
The other two answers are great. Remember too that most tribes are photographed and described by people primarily from the West. We have an idea of what it means to be "a tribe" and we intentionally or unintentionally portray people in the same way because that is what it means to be a tribe to us. We also define what it means to be in a tribe so we collapse the variability to fit our own types.
But also tribes, and all cultures more broadly, are hugely diverse and really aren't the same. Even separate historically-related communities living in the same region will often have great differences, so someone from PNG and someone from the Amazon will be very different with different ideas, ideals, materials, worldview, etc.