To perform the subtraction \(8.03 \times 10^{-8} - 2.55 \times 10^{-2}\), we first need to express both numbers in the same power of ten.
The number \(2.55 \times 10^{-2}\) can be converted into scientific notation with a power of ten that matches the \(10^{-8}\) in the first term. We can rewrite it as follows:
\[ 2.55 \times 10^{-2} = 2.55 \times 10^{-2} \times \frac{10^{6}}{10^{6}} = 2.55 \times 10^{4} \times 10^{-8} = 25,500 \times 10^{-8} \]
Now, we can rewrite the equation:
\[ 8.03 \times 10^{-8} - 25,500 \times 10^{-8} \]
This becomes:
\[ (8.03 - 25,500) \times 10^{-8} = -25,491.97 \times 10^{-8} \]
To express it in scientific notation, we convert \(-25,491.97\) into a form that has one digit to the left of the decimal:
\[ -25,491.97 = -2.549197 \times 10^{4} \]
Thus, combining this with \(10^{-8}\):
\[ -2.549197 \times 10^{4} \times 10^{-8} = -2.549197 \times 10^{-4} \]
So, the final answer is:
\[ \boxed{-2.549197 \times 10^{-4}} \]