Logic Masters Deutschland e.V.

This is a puzzle for Scojo's Setting Saturday Prompt last year.
RULES
(1)Normal Skyscraper Sudoku Rules apply: Place the digits 1 through 9 in each empty cell. Digits must not repeat within the same row, column, or box. Every digit outside the grid represents a skyscraper with the same height. Clues outside the grid indicate the number of visible skyscrapers from that side. Higher skyscrapers block the view of lower ones.
(2)For each dot, it has a value of X if adjacent digits seperated by the dot are in an 1:X ratio.
(3)For the dots colored red, green and blue, the value can be 2,3,4; Each color of such dots has only one value it identifies as.
(4)For the dots colored yellow, the X must be 5 or more; Different yellow dots have different values.
(5)It's up to the solver to deduce the value of each dots and there are no negative constraints.
CLICK THE PICTURE TO SOLVE IT↓

Any feedback is welcome and appreciated. Wish solvers a good luck.