Correct translation for Black/White russian words

I started translate on russian, but stumbled into some problem, using names of stone color in puzzle descriptions. It works fine for russian words Черные/Белые (a puzzle put correct word to description text, depends of color set in the board), but not working for some other word form, like Черных, Черный, Черными etc.

Beside that, it appears like the color swapping only for first occurence, I put another word Черные in the end description, and it doesn’t change when I swap colors on the board.

Can you help me?

Puzzle with such problem -, for example.