First, open your ROM with VBA and go to the place where there's something you want to change its colors. Then go to Tools -> Map Viewer.
There's 4 backgrounds, 0, 1, 2 and 3. The textbox is in BG0. Choose the colors you want to edit from the textbox and write its RGB down in notepad.
We want to edit the blue colors from the textbox, in notepad we should have: 19 25 31 and 15 23 28
Now go back, and go to Tools -> Palette Viewer.
Look at all the blue colors until you find two blue ones that their RGB numbers match with the ones from the textbox.
The blue colors of the textbox are there, so we'll have to search for the whole palette in the hex editor (the one in the red circle). If you just search for the two colors, you may edit something else.
The blue color's value that's selected in this picture is "7F33". To search for the palette in the hex editor, you have to write down the values of all the colors in the palette. But to work, you have to flip the first two digits with the last two digits of each value. For example, "7F33" should be "337F".
When you finish writing all the values down and flipping the first two digits with the last two digits you should have: 000029251F00E003007CFF03E07F1F7C5A67000000009C77FF7F337FEF72FF7F
Now, open your ROM in a hex editor, and search for that as a "hex string".
The hex editor finds the string at offset "1E66B0". Go to "337F" and "EF72", edit them and save. Now you'll need A-Color, find a picture with the colors you want to use, open it in Paint, and choose the colors with the colorpicker. Then go to Colors -> Edit Colors and you'll find the color's RGB numbers.
Now open A-Color, put the RGB numbers and select "Give Me My Color!".
Now, flip the first two digits with the last two of the Hex Value, and replace the textbox's blue colors in the hex editor with the two new orange ones.
At the offset "1E66B0", find the two blue colors ("337F" and "EF72") and replace them with "5F13" and "1F2F", the hex values of the two orange colors. Then save. Now open the ROM with VBA.
Do you know why When I try to change the Tree Colors in Pokémon FireRed to a Pokémon Diamond Tree Color, It always changes Red,yellow and very Light Green. I have the Correct colors and their offsets if it helps:
0000 F747 5033 471A 6709 - The Colors I want to change 0000 F747 5033 471A 6709 8E31 E818 1F7C 715F 1F3B 1D36 D820 9463 2E53 C846 8336 - The whole Color palette.
I want to Over Write the Green Colors with these colors: 4315 36B1 260B 2987 2147 - But I don't know if I could add Palettes(By the way those colors are From Zel's Tree Tiles, I am not going to use his Tree Tile Just the Color).