The requirements and color mode selection for brochure printing are as follows:

1. Resolution: In order to achieve high-quality printing effects, the images in the brochure should have sufficient resolution. Usually, it is recommended to use a resolution of 300 dpi (dots per inch) to ensure clarity and detail.

2. Color mode: In the printing process, there are two commonly used color modes: CMYK and Pantone. CMYK is a four color printing mode suitable for color printing, consisting of four colors: cyan, magenta, yellow, and black. Pantone is a spot color printing mode that uses specific color ink cartridges for printing. Choose the appropriate color mode based on specific needs.

3. Color accuracy: To ensure the color accuracy of the brochure printing, it is recommended to use a color correction system, such as the ICC (International Color Consortium) configuration file. This can ensure consistent color effects on different devices and printing machines.

4. File format: Common album design file formats include PDF, AI, EPS, etc. Ensure to embed images and text into the file and convert the font to curves to avoid display issues during output.

5. Image Embedding: If you have used images in your brochure, make sure to embed them into the design file so that they can be displayed correctly during the printing process. Meanwhile, ensure that the images used have sufficient resolution and clarity.

6. Color correction and samples: Before large-scale printing, color correction and sample making are required. This can ensure that the color of the printed material matches your expectations.

Please note that the above are general recommendations, and specific requirements and choices may vary depending on your specific printing project and the requirements of the printing factory. It is recommended to communicate with printing manufacturers and understand their specific requirements before cooperating with them.