I actually like this. Some comments:
- The colour for Manchukuo should probably be the same as the colour for Changchun, since that was the capital of Manchukuo.
- It is very odd to me that Han Dynasty and Beijing/Yuan Shao would share the same colour, since Hebei historically has never been a capital of Han. My personal suggestion would be for Hanzhong and Han Dynasty to share a colour, since the "Han" in their names has a common origin.
- You should include Zhao as an alternate use for Handan.
- You should include Dai and the Tuoba Wei as an alternate use for Northern Shanxi.
- You should include Wei as an alternate use for Southern Shanxi.
- The Taiyuan colour should be able to be used for any Jin (since they were all based in this area), including the Jin Dynasty and the Later Tang, but not Jurchen Jin
- I suggest that Kaifeng, Zhengzhou, and Song Dynasty share one colour. Zhengzhou is the modern capital of Henan, but historically Kaifeng was the most important city in Henan between the 11th century and the 20th century. But they are close to each other and I cannot remember any period where Zhengzhou and Kaifeng were the centres of rival polities, so they can share the same colour. Instead of Pingdingshan being the tertiary Henan colour, I would suggest either Nanyang or Caizhou/Zhumadian.
- I also suggest that you have an Anyang/Pingyuan/Shang Dynasty colour.
- Why do Shandong and Jinan not share a colour? Jinan has always been the capital of Shandong. My personal suggestion for colours in Shandong is:
1. Jinan/Qi/Primary Shandong
2. Jining/Lu/Southern Shandong
4. Weihai/Jiaodong/Shandong Peninsula/secondary British China/Northern Chinese thalassocracy
Having a Mount Tai colour is unnecessary in my opinion.
- Zhou Dynasty's colour should obviously be the same as the Xi'an/Shaanxi colour. By "Northwestern Clique", I assume you mean Yang Hucheng's armed forces? This colour should really have Feng Yuxiang and the Guominjun as an alternate use, since Yang Hucheng was a subordinate of Feng Yuxiang. It doesn't make that much sense to have Feng Yuxiang be an alternate use for Ningxia.
- I think you should have Qin Dynasty as an alternate use for the Eastern Gansu colour.
- My suggestion is to just get rid of the Gansu colour. Tuyuhun should be an alternate use for the Tangut colour.
- I also suggest that you have a Northern Shaanxi/Yulin colour. Given that there isn't really any other good place to put the Tang Dynasty, I suppose you could have Tang Dynasty as an alternate use for this colour as well.
- I'm not sure why "Hetao" is an alternate use for the Lanzhou colour. What does that mean exactly? Lanzhou is the modern capital of Gansu (though during the Ming Dynasty the capital of Gansu was in Hexi).
- The Yugurs should actually be an alternate use for the Hexi colour, not the Dunhuang colour. The only Yugur state to have existed in history was the Ganzhou Uyghur Kingdom, which was in Hexi, and not around Dunhuang. Switch the colours around if you really want the Yugurs to be yellow.
- There really needs to be a colour for a Huaihai/Xuzhou/Northern Jiangsu state.
- The colours you have in the Jiangnan section are a bit weird and I'd suggest them to be redone as the following:
1. Anhui/Ming Dynasty/Chu
2. Northern Jiangsu/Huai River-based state/Xuzhou/Southern Qi
3. Central Jiangsu/Yangzhou/Sui Dynasty
4. Primary Jiangsu/Nanjing/Eastern Wu
5. Secondary Jiangsu/Zhenjiang/Liu Song
6. Shanghai/Suzhou/Jiangnan/Wu (Spring and Autumn) (I'm not aware of any time Suzhou and Shanghai were capitals of rival states, and they're both basically just alt capitals for the same region)
7. Zhejiang/Hangzhou/Wu (Ten Kingdoms)
8. Kuaiji/Shaoxing/Yue (Spring and Autumn)
9. Southern Zhejiang/Ouyue
10. Zhoushan Islands/East Chinese thalassocracy
In general, I think that the Jiangnan category should actually be in the South China section. Also, rename it to "Eastern China" or "Lower Yangtze Region". And move the Fujian colours to this section.
- I would suggest that Southern Liang (rather than Liu Song) be the dynastic alternate for Hubei. Since the founder of Southern Liang had his army stationed in Xiangyang before he took the capital.
- If the Nanchang colour is supposed to be for a Poyang Lake-based state, it should say Jiujiang, not Nanchang. Nanchang is the capital of Jiangxi (always has been) and it is on the Gan River.
- My suggestion is for you have one colour that is Shenzhen/Huizhou/Dong River/Chen Jiongming, another colour that is Eastern Guangdong/Chaoshan, another colour that is Hakka/Taipings/Southern Jiangxi, and another colour that is Inland Fujian/Nanping
- The Guangxi colour should refer to Liuzhou specifically and not Guangxi in general, since the fact that you include the Zhuangs as an alternate use implies that you really mean the western part of the province here, and Nanning and Guilin are the actual historical capitals of Guangxi.
- I'd suggest having "Zhaoqing/Xi River" rather than "Taishan/Sze Yup/Western Guangdong", since Zhaoqing is historically an important city. There was a time when Guangzhou and Zhaoqing hosted rival factions of Southern Ming.
- Nanzhao should really be an alternate use for the Primary Yi colour, since it was the ethnically Yi state.
- Qin Dynasty being an alternate use for Guizhou makes utterly no sense. The Qin Dynasty didn't even control Guizhou. Same for Xiamen/Liang Dynasty. Hunan/Tang Dynasty is also inexplicable, and Eastern Wu/Wuzhou, and Leizhou/Shi Xie. People are going to be confused when they can't find these dynasties in the North China part of the key.
- Actually, delete the Hunan colour. It's not doing anything that isn't already being done by the Changsha colour. Changsha is on the Xiang River. Unless you want to use the Hunan colour for, say, Hengyang.
- Add Xiangxi as an alternate use for the Huaihua colour.
- "Formosan Mainland China" should really be moved from Fujian to Xiamen in my opinion.
- I'm sure this is standard for you, but is there really a good reason for having this many colours for random uninhabited islands in the South China Sea? As opposed to having more colours in places where there are actually likely to be multiple states, I mean.
- I suggest that you use "Middle Yangtze Region" instead of "South Central China".
- I suggest that you use "Liangguang" or "South China sensu stricto" instead of "Lingnan".
- Why can't the last section just be called "South China Sea Islands"? Are Taiwan and Hainan not islands in or around the SCS?
- Sichuan should be with Chuanxi, not Chuanbei. I don't think the capital of Sichuan has ever been in the northern province, it has always been at Chengdu.
- Maybe add a "Wanxian/Wushan" colour and an "Other Sichuan" colour, so the division of Sichuan during the late warlord period can be represented with this colour scheme (Liu Wenhui:Chuannan, Liu Xiang:Chongqing, Deng Xihou:Chuanxi, Tian Songyao:Chuanbei, Yang Sen:Wanxian, Liu Cunhou:Other Sichuan).