(there has been no progress on updating of my old links)
For no particular reason, I have changed the colour scheme of my main blog to match the seasons. I have no plans to do the same for the Japanese version which uses the same layout.
The current one is for Summer (green, blue), which is from July to September, but since summer will be ending in less than a month, the autumn colour scheme (yellow, orange) will be made around 22 September. Winter (early December) and Spring (pink, blue; April) too. I might do the same for Halloween (orange, black ; end of October), Christmas (white, green, red; end of december), and New Year's too (black, white; 3 days before to early January).
I don't know if I should also do a banner for each to match. The current one seem more suitable for winter.