The color of a compound is often determined by the transition metal ion present in it and the oxidation state of that metal ion.

i. ZnSO4: Zinc sulfate is a white compound. Zinc ions (Zn^2+) typically do not exhibit any color in solution.

ii. CuSO4: Copper sulfate is blue in color. Copper ions (Cu^2+) in solution often exhibit a blue color due to the presence of partially filled d orbitals.

iii. FeSO4: Iron(II) sulfate is pale green in color. Iron(II) ions (Fe^2+) typically give a green color to solutions due to the presence of partially filled d orbitals.

iv. FeCl3: Iron(III) chloride is yellow-brown in color. Iron(III) ions (Fe^3+) often exhibit a yellow or brown color in solution.

Therefore, among the given options, only (i) ZnSO4 is white in color.

So, the correct answer is (i) ZnSO4.