To Cynook:
Draw a custom coin tile in GFX28/29 and insert the GFX. Now use SMWSBE (SMW Status Bar Editor) and press 7 to change to the white palette. Localize the coin that you just made and click it. Click the coin of the normal coin counter (above the score). Now select the 0 and click the yellow 0 located below the "TIME" word. Select a blank/black tile and replace the two black tiles (to the left of the 0) using those tiles. You may want to do the same with the "TIME" word. Then press S to save. Test the ROM on your emulator.
Draw a custom coin tile in GFX28/29 and insert the GFX. Now use SMWSBE (SMW Status Bar Editor) and press 7 to change to the white palette. Localize the coin that you just made and click it. Click the coin of the normal coin counter (above the score). Now select the 0 and click the yellow 0 located below the "TIME" word. Select a blank/black tile and replace the two black tiles (to the left of the 0) using those tiles. You may want to do the same with the "TIME" word. Then press S to save. Test the ROM on your emulator.