Small spaces require special treatment when it comes to interior design.
Maximizing space utility represents a priority, whilst the colour, dimensions and style of the furniture and design in general have to be light, functional and adequate in dimensions. Therefore, the design that I propose derived from the necessity of creating an open, comfortable space which would have a lot of storage space while successfully addressing all the parameters you wished for, but would not depict the feeling of restriction, typical for small apartments.
This is the reason why I chose white as a dominant colour ( present in the wooden flooring and wall coating ). It represents a light canvas on which any colour could be applied, so I choose furniture rich in colour to add a little friskiness to the design. (:
Earth and beige tones could go great too, if preferred.
The proposed zone disposition dictates the removal of unnecessary barriers ( walls and doors ), as well as the repositioning and reorganizing the existing kitchen space. By inserting division panels and sliding doors the existing plan becomes a fully functional open space, differentiated into adequate rooms by the choice of the materials and furniture design.
Your new apartment would have a bathroom with a shower and storage space, a small entrance hallway storage space leading into the open main area ( living room / library / kitchen / dinning room ) and a modular bedroom with storage space.