Check the Eyedropper tool
There's also extended eyedropper tools for sale
Copying styles in InDesign is simple. Use the eye dropper tool to select the source style by clicking it on text with the style already applied, then move to the un formatted text and click and drag over the text you wish to apply the style to, or simply click anywhere in a paragraph and the whole paragraph will be formatted.
A bit of a clumsy workaround and ID does not (without making your own shortcuts) allow you to select tools with the keyboard when in text mode.
But it is better than nothing
Well that's the idea behind KBSC you can always remap any shortcut to whatever suits.
Go to edit>keyboard shortcuts
Product Area: Tools
Select the Eye dropper Tool
Insert the KBSC you want and then change the CONTEXT to Text
I just changed mine to CTRL SHIFT I – and now when I have text highlighted I can hit the KBSC select a colour to sample.