The base color just appears differently with some of the color rules, a good example would be the Compound rule, one of the spindles will have an additional inner circle denoting that it is the base. The Android app doesn't allow you to redefine a certain swatch to be the base like the browser based version. I agree, manually entering a value and an option to set a swatch as the base would be a great feature additions.
Thanks for the reply.
Where can we suggest this feature?
Surely it would be so simple to add an option to specify a base color?
It really does make the Android App fairly useless for working on an existing color specification where a base color has been previously defined.