What is thermal resistance of SMD7530 similar to this photo (Or typical LED in this type):
With this datasheet:
I cannot find any thermal resistance in it's datasheet.
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Since the maximum junction temperature is 120°C and the maximum current is 150mA, you can guess that the thermal resistance is such that 95°C of rise occurs at 0.465W given the typical forward voltage is 3.1V, so about 204K/W.
However that number is essentially useless since you don't know anything about the conditions under which that number is valid. It could be 20 x 20mm of aluminum core PCB, for example. If you assume that number and use FR-4 with modest amounts of thin copper, the LED life may be greatly foreshortened.