How to change glyph layer color from black to Foreground in color font for

Hy!
I am working on a color font in which each glyph consists of multiple layers, Actually it is an Arabic Quran font, I am applying intonation (Tajweed) rules by coloring different parts of glyphs in different layers. Almost I had completed the font but unfortunately I had applied all glyph base color as black instead of foreground color (based on user choice) Now I want to change black color into foreground color. (so that the user can change the base color of his choice but the colored part remains same, it will also be helpful in using the font in night mode) I had tried it to do manually one by one each glyph, but it takes a lot of time because there are almost 150000 glyphs in my font. so I want to find out a way how can I set this in a single command. I want automation to complete my job in time. is there is any scripts that will solve my problem? I am using Font Creator 13 software and using CPAL and COLR tbales.
Please guide me. Thanks alot..

I have coloured glyphs in my Odana font, which will change colour simultaneously when I edit the palette colour. I tested with FC13. I don’t see how one applies a glyph base colour. I guess there is no solution. Have you tried selecting multiple glyphs in the overview before making the palette changes?

Before
Globe After.png
After
Globe Before.png

We can not apply any color without opening an glyph editor window. and in glyph editor window we can only apply the color on that particular glyph. we can not apply any color to all glyphs.

Editing the colour in the palette applies the change to all glyphs using that palette colour, as per my screenshots.

thnaks, but what is the hexacode for foreground color in Font creator?

The foreground colour can be anything you want. Different glyphs can use different palette entries for their foreground colour. If you need more colours, add them to the palette, and apply them to the coloured glyphs.