Which of the following is/are the application(s) of chromatography?

All of these

The correct answer is option 4. All of these.

Chromatography is used for various applications, and all the options mentioned are correct:

1. To separate colors in a dye:

Chromatography is commonly used to separate and analyze different components in a dye, revealing the individual colors present.

2. To separate pigments from natural colors:

Chromatography is employed in the separation of pigments in natural colors, such as those found in plants or other biological materials.

3. To separate drugs from blood:

Chromatography is also used in pharmaceutical and forensic settings to separate and analyze components, including the separation of drugs from complex mixtures like blood.

So, all of the provided options are valid applications of chromatography.