On Home Page we used Slidershow (full width) addon from SP Page Builder Pro.To remove background color layer (overlay) from slidershow addon please use following custom CSS code:

.sppb-slider-wrapper.sppb-slider-fullwidth-wrapper .sppb-slideshow-fullwidth-item-bg::before 
{background: transparent !important;}

Using this class you can also control of used layer bg color or transparency lever based on RGBA colors scheme. Example CSS code to make BG color few tones lighter:

.sppb-slider-wrapper.sppb-slider-fullwidth-wrapper .sppb-slideshow-fullwidth-item-bg::before
{background: rgba(14,66,156,0.4);}

Custom CSS code can be used inside template settings (Custom CSS) or inside custom.css file, which have to be created first. More in Helix3 Manual.