Change color of white emojis (:one:, :two:, etc) to blue.
Change color of white emojis (:one:, :two:, etc) to blue.

The following emojis are colored white (with a transparent background)
and are hard to read in the context of Zulip. This commit changes their
colors to blue. The emojis are:

hash, zero, one, two, three, four, five, six, seven, eight and nine.

This fixes #1969.

brockwhittaker/zulip,souravbadami/zulip,sonali0901/zulip,vaidap/zulip,zacps/zulip,kou/zulip,jackrzhang/zulip,tommyip/zulip,TigorC/zulip,zacps/zulip,jrowan/zulip,jackrzhang/zulip,amanharitsh123/zulip,dattatreya303/zulip,ryanbackman/zulip,vaidap/zulip,AZtheAsian/zulip,susansls/zulip,rishig/zulip,KingxBanana/zulip,verma-varsha/zulip,rishig/zulip,niftynei/zulip,arpith/zulip,zulip/zulip,cosmicAsymmetry/zulip,eeshangarg/zulip,dhcrzf/zulip,AZtheAsian/zulip,andersk/zulip,TigorC/zulip,amyliu345/zulip,sharmaeklavya2/zulip,jackrzhang/zulip,zacps/zulip,tommyip/zulip,mahim97/zulip,kou/zulip,blaze225/zulip,timabbott/zulip,souravbadami/zulip,blaze225/zulip,Galexrt/zulip,niftynei/zulip,mahim97/zulip,joyhchen/zulip,blaze225/zulip,arpith/zulip,samatdav/zulip,amanharitsh123/zulip,j831/zulip,sharmaeklavya2/zulip,cosmicAsymmetry/zulip,andersk/zulip,dawran6/zulip,synicalsyntax/zulip,amanharitsh123/zulip,JPJPJPOPOP/zulip,JPJPJPOPOP/zulip,brockwhittaker/zulip,zulip/zulip,vabs22/zulip,amyliu345/zulip,jainayush975/zulip,dawran6/zulip,samatdav/zulip,sonali0901/zulip,jackrzhang/zulip,synicalsyntax/zulip,dhcrzf/zulip,Galexrt/zulip,christi3k/zulip,tommyip/zulip,amyliu345/zulip,vaidap/zulip,blaze225/zulip,SmartPeople/zulip,JPJPJPOPOP/zulip,punchagan/zulip,joyhchen/zulip,vabs22/zulip,christi3k/zulip,sonali0901/zulip,dattatreya303/zulip,hackerkid/zulip,dhcrzf/zulip,souravbadami/zulip,jphilipsen05/zulip,timabbott/zulip,jrowan/zulip,kou/zulip,mahim97/zulip,Diptanshu8/zulip,samatdav/zulip,Juanvulcano/zulip,TigorC/zulip,punchagan/zulip,niftynei/zulip,mahim97/zulip,rht/zulip,timabbott/zulip,amanharitsh123/zulip,SmartPeople/zulip,amyliu345/zulip,jrowan/zulip,vabs22/zulip,arpith/zulip,verma-varsha/zulip,dawran6/zulip,brainwane/zulip,Juanvulcano/zulip,jackrzhang/zulip,shubhamdhama/zulip,sharmaeklavya2/zulip,rishig/zulip,aakash-cr7/zulip,jackrzhang/zulip,Diptanshu8/zulip,shubhamdhama/zulip,niftynei/zulip,showell/zulip,cosmicAsymmetry/zulip,arpith/zulip,joyhchen/zulip,verma-varsha/zulip,christi3k/zulip,PhilSk/zulip,dhcrzf/zulip,j831/zulip,ryanbackman/zulip,aakash-cr7/zulip,susansls/zulip,eeshangarg/zulip,rishig/zulip,verma-varsha/zulip,ryanbackman/zulip,zacps/zulip,hackerkid/zulip,isht3/zulip,andersk/zulip,zacps/zulip,showell/zulip,jphilipsen05/zulip,rishig/zulip,timabbott/zulip,SmartPeople/zulip,dawran6/zulip,rht/zulip,kou/zulip,SmartPeople/zulip,brainwane/zulip,eeshangarg/zulip,SmartPeople/zulip,jrowan/zulip,JPJPJPOPOP/zulip,shubhamdhama/zulip,synicalsyntax/zulip,arpith/zulip,AZtheAsian/zulip,hackerkid/zulip,brainwane/zulip,synicalsyntax/zulip,brockwhittaker/zulip,jainayush975/zulip,christi3k/zulip,Galexrt/zulip,Diptanshu8/zulip,tommyip/zulip,jrowan/zulip,brockwhittaker/zulip,mahim97/zulip,KingxBanana/zulip,sonali0901/zulip,brainwane/zulip,souravbadami/zulip,PhilSk/zulip,synicalsyntax/zulip,jainayush975/zulip,showell/zulip,isht3/zulip,sonali0901/zulip,vaidap/zulip,j831/zulip,Juanvulcano/zulip,vabs22/zulip,souravbadami/zulip,cosmicAsymmetry/zulip,niftynei/zulip,andersk/zulip,AZtheAsian/zulip,sharmaeklavya2/zulip,zulip/zulip,timabbott/zulip,brockwhittaker/zulip,cosmicAsymmetry/zulip,JPJPJPOPOP/zulip,AZtheAsian/zulip,KingxBanana/zulip,jackrzhang/zulip,susansls/zulip,Galexrt/zulip,samatdav/zulip,brainwane/zulip,punchagan/zulip,jainayush975/zulip,dhcrzf/zulip,andersk/zulip,PhilSk/zulip,souravbadami/zulip,JPJPJPOPOP/zulip,sonali0901/zulip,amanharitsh123/zulip,sharmaeklavya2/zulip,isht3/zulip,Galexrt/zulip,hackerkid/zulip,dattatreya303/zulip,mahim97/zulip,tommyip/zulip,isht3/zulip,brainwane/zulip,tommyip/zulip,blaze225/zulip,j831/zulip,timabbott/zulip,synicalsyntax/zulip,rishig/zulip,rht/zulip,punchagan/zulip,joyhchen/zulip,vaidap/zulip,sharmaeklavya2/zulip,dawran6/zulip,isht3/zulip,hackerkid/zulip,joyhchen/zulip,aakash-cr7/zulip,jphilipsen05/zulip,amyliu345/zulip,Juanvulcano/zulip,aakash-cr7/zulip,AZtheAsian/zulip,vabs22/zulip,zulip/zulip,eeshangarg/zulip,kou/zulip,andersk/zulip,ryanbackman/zulip,andersk/zulip,rht/zulip,synicalsyntax/zulip,shubhamdhama/zulip,KingxBanana/zulip,christi3k/zulip,susansls/zulip,aakash-cr7/zulip,isht3/zulip,Juanvulcano/zulip,showell/zulip,niftynei/zulip,amyliu345/zulip,aakash-cr7/zulip,jphilipsen05/zulip,joyhchen/zulip,dattatreya303/zulip,Juanvulcano/zulip,KingxBanana/zulip,showell/zulip,rht/zulip,verma-varsha/zulip,hackerkid/zulip,rht/zulip,KingxBanana/zulip,TigorC/zulip,eeshangarg/zulip,punchagan/zulip,christi3k/zulip,shubhamdhama/zulip,blaze225/zulip,punchagan/zulip,rishig/zulip,susansls/zulip,jrowan/zulip,PhilSk/zulip,jphilipsen05/zulip,tommyip/zulip,dawran6/zulip,zacps/zulip,zulip/zulip,brainwane/zulip,amanharitsh123/zulip,cosmicAsymmetry/zulip,TigorC/zulip,samatdav/zulip,jainayush975/zulip,Galexrt/zulip,TigorC/zulip,eeshangarg/zulip,zulip/zulip,Galexrt/zulip,dhcrzf/zulip,vaidap/zulip,kou/zulip,samatdav/zulip,susansls/zulip,jainayush975/zulip,hackerkid/zulip,timabbott/zulip,punchagan/zulip,ryanbackman/zulip,kou/zulip,Diptanshu8/zulip,arpith/zulip,rht/zulip,eeshangarg/zulip,j831/zulip,zulip/zulip,verma-varsha/zulip,PhilSk/zulip,brockwhittaker/zulip,shubhamdhama/zulip,dhcrzf/zulip,PhilSk/zulip,Diptanshu8/zulip,showell/zulip,dattatreya303/zulip,showell/zulip,Diptanshu8/zulip,dattatreya303/zulip,SmartPeople/zulip,ryanbackman/zulip,jphilipsen05/zulip,shubhamdhama/zulip,j831/zulip,vabs22/zulip