each effect can have totally different colors. the colors are saved when you save the effect.
modify the 6 colors and then save as a palette.
when you first launch xlights, do a load palette from saved colors
now all effects you create will start with those colors./
If you created 100 rows, with the default colors. you now change one of them, the others will not see that change.
you can use an editor and change the colors you have
here are the patterns for effect1 and effect colors
If i go into an editor and open the sequence xml
i could do a search and replace and change
E1_BUTTON_Palette2=#FFFF00"
with
E1_BUTTON_Palette2=#FFFFFF
after this the second color of effect 1 is going to be pure white,
If you do decide to edit your sequence file
"FILE,BACKUP" Please!
here are patterns for 6 colors for both effect1 and effect2
E1_BUTTON_Palette1=#8000FF,E1_CHECKBOX_Palette2=0,E1_BUTTON_Palette2=#FFFF00,E1_CHECKBOX_Palette3=0,E1_BUTTON_Palette3=#FF0000,E1_CHECKBOX_Palette4=1,E1_BUTTON_Palette4=#00FF00,E1_CHECKBOX_Palette5=1,E1_BUTTON_Palette5=#0000FF,E1_CHECKBOX_Palette6=0,E1_BUTTON_Palette6=#FF8000,
E2_CHECKBOX_Palette1=1,E2_BUTTON_Palette1=#FF0000,E2_CHECKBOX_Palette2=0,E2_BUTTON_Palette2=#00FF00,E2_CHECKBOX_Palette3=0,E2_BUTTON_Palette3=#0000FF,E2_CHECKBOX_Palette4=0,E2_BUTTON_Palette4=#FFFF00,E2_CHECKBOX_Palette5=0,E2_BUTTON_Palette5=#FFFFFF,E2_CHECKBOX_Palette6=0,E2_BUTTON_Palette6=#000000