tt-rss/schema/versions/mysql/53.sql

alter table ttrss_labels2 add column fg_color varchar(15);
update ttrss_labels2 set fg_color = '';
alter table ttrss_labels2 change fg_color fg_color varchar(15) not null;
alter table ttrss_labels2 alter column fg_color set default '';

alter table ttrss_labels2 add column bg_color varchar(15);
update ttrss_labels2 set bg_color = '';
alter table ttrss_labels2 change bg_color bg_color varchar(15) not null;
alter table ttrss_labels2 alter column bg_color set default '';

update ttrss_version set schema_version = 53;