Why the Halftone Pattern Filter change the color of the layer?

Alright, I managed to get everything right. I just changed RGB color channels of the text layer after I put the Halftone Pattern effects and it works. Thanks everyone for your help.

Your text with only the blue channel enabled is in a smart object. That smart object presents as a full RGB image but only blue used i.e. RGB 0,255,0

When you apply the half tone filter to the smart object it uses the current foreground and background colours to make the toned dots or lines, and you have those colours set to white and black.

You have a choice. Either set the foreground colour to blue, background to black and re-apply the half tone filter.

or

Set the smart object to use the blue channel only in blending options.

Dave

Could you please post screenshots with the pertinent Panels (Toolbar, Layers, Options Bar, …) and the Layer Style dialog visible? 

The Halftone Pattern filter can change the color of a layer due to its inherent nature of manipulating tones and creating a pattern of dots. This filter applies a series of dots or pixels to an image or layer, simulating a halftone printing effect commonly used in print media. When the dots are placed in specific patterns, they can alter the appearance of colors by visually blending or dithering them. As a result, the original colors may be distorted or modified, leading to a different color perception in the final image or layer. In terms of text sound, imagine applying the Halftone Pattern filter to a layer with colorful text. The dots created by the filter could merge the original colors of the text, resulting in a new color that differs from the original.