Can anyone explain this rule of giving color in tajweed.

[jawwad-iqbal22]

Assalam Walaikum,

I am not RoR Developer, i am unable to understand one thing in tajweed

character dal has a color grey but in html code it dont have

So i am confuse how its getting this color and how many other rule are apply in this way in project (i have seen another situation like this in project), if anybody can explain me them will be very thankful.

I am looking for the list of rules or function which following this way.

And sorry for my english

Lastly, Can anyone share me the file location of a font use in coloring tajweed thank you

[benomaire]

I believe the د should not be in gray.
Anyway please have a look at the new site: https://next.quran.com